Tape addressed to Joshua Lederberg of The Rockefeller University in
New York City in response to a note from Joshua Lederberg of May 16, 1986
requesting information on the history of the transduction by the 
bacteriology phage lambda.

     Good to hear again from you Joshua.  I haven't seen you in quite a few
years but I keep noticing your activities.  All goes well here and I'll
perhaps later on tell you of some of the things that are going on but in
response to your general questions I think I'll start at the other end of
your list of questions and they specifically relate as to how I got to the
University of Wisconsin.  I had completed a Masters Degree in microbiology
at the University of Kentucky in 1947 and after that time I went to work in
the Biology Division of Oak Ridge National Laboratory with a E.H. Anderson.
Anderson should be remembered for two things for sure.  One is that he
was the person who created the M-9 mimimal medium which many people use in
growing E-coli.  The other thing is that prior to his going to Oak Ridge 
which occurred in early 1947 that he had been at Vanderbilt with Max
Delbruck and at Vanderbilt he had discovered that certain classes of E-coli
B mutants resistant to T1 required tryptophane for growth.  They were the
result of a deletion of trytobane region and I presume also the receptors
for the T1 phage.  Anderson came to the Biology Division and set up a section
there and I joined him as one of his technicians and the objective of the
research was to see if there were other phage resistant mutants which had
nutritional requirements and I worked for him for a couple of years.  We
irradiated E.coli B with electrons from radiactive phosphorus.  We had
these petri dish size phosphorus plaques which were about 90% pure 
phosphorus.  They had been steeped in the Oak Ridge pile and were very
hot and we used them to irradiate E.coli cells which were then allowed to
grow up into colonies and the colonies were picked and tested and I was
responsible for testing the resistance of these radiation survivors with
bacteriophages of the T series T1 through T7 and I think we must have 
scored somewhere around 60,000 colonies by hand using this technique and
I don't remember now I think he found some additional nutritional 
requirements but I don't think there was any simple correlation with
phage resistance.  And it was during that time that I became first aware
of your work with Tatum.  It was discussed in the laboratory, the Journal
of Bacteriology paper in particular.  And after a couple of years with
Anderson I moved into the Biochemistry Division with a Nick Carter, Charles
Edward Carter, who was a biochemist M.D. from the I think the National Cancer
Institute where he had been affiliated with Jesse Greenstein and he was a
close friend of Alex Hollander the Director of the Biology Division.  And I
joined his group to work on the synthesis of nucleic acids and E.coli and
also Bacillus subtilis. I had done some early work on the comparison 
between E.coli B and E.coli B/r and had noted some things about differences
in their pattern of synthesis of nucleic acids and the fact that the B/r
strain that I was working with seemed to arrest the stationary cultures
at a different position in its growth cycle such that it contained several
nuclei whereas the B strain only contained on the average one nucleus so 
there was a nucleic acid difference between the two strains.  And it was
during this interval that you came to the Biology Division to give a
seminar which I believe must have been about the time you were working on
the persistent heterozygotes of E.coli because I can recall the slides
showing the segregation sectoring of the colonies the one that is in the
Proceedings of the National Academy of Science paper that you published
around I guess 1947 or 48 and during that visit there you came and visited
all the laboratories and the one in which I was involved and we discussed
my work and some other things and at the conclusion of that discussion you
said that if I ever decided to go back to school and work on my Ph.D. to
let you know.  And so a couple of years later, several years later as a 
matter of fact it was in the spring of 1950 or 51 I think 51.  Well
Hollander used to come around and bug me every day about going back to school
and completing my education and I think it was April of 1951 that he came to
the laboratory and for the umpteenth time said "when are you going to school"
and I said to him "I'm going to go to school in September".  I was tired of
his nagging and so I wrote to you and we exchanged letters and you agreed 
to sponsor me at the University of Wisconsin.  So in August of 1951 I
packed up my family, my wife Helvise and my daughter Margaret who was then
only about two years old. I had bought a 1931 model A Ford and so we
packed everything up and got into it and set sail for Madison which took us
about two days to get there.  I had borrowed a house trailer from my parents
who lived in Florida and they weren't using it at that time and so we had
it set up at a trailer park on the south side of Madison, Lake Minona I
believe it was.  The park was called Happy Acres Trailer Park.  And so I
began working in the laboratory in the fall of 1951 and my page #1 in my
notebook the first page, is dated October 5, 1951 and that's when
I entered your laboratory.  I was there I believe for a couple of weeks
before you offered me a job to work in the laboratory and I was given a
number of things to work on which I'll speak of in a minute or two.  Now
one of your questions has to do with my notebooks.  Now I have three
volumes from that period in Madison from the fall of 51 until I left in
June of 1956 and I have three volumes, each about 200 pages.  Volume 1,
Volume 2 and the third volume is a summary of various things taken from
the early volumes.  Now you ask about having copies of them.  I'd be glad
to give you whatever you'd like.  If your going to have a permanent 
repository somewhere I could even contribute them to that if you wish
otherwise I'll try and make you copies but it will be a little while before
I can copy them because each one of them is about 200 pages.

     The first experiments that I did in the laboratory had to do with the
fact that you had an atomic energy grant that had to do with the radiation
resistance of haploid and diploid strains of E.coli and I'm going to include
with this tape actually a copy of a report that you wrote to the AEC that
covers the interval from March 1, 1952 to February 28, 1953 and its 
dated March 1, 1953 and it covers a number of things but it also gives your
written summary of the early observations on lambda and lambda transduction.
Now as you remember when we joined the laboratory there each one of us in
the laboratory was given an assignment.  Mine was to study the radiation
resistance and the induction of prophages in K12 and I have a number of
figures here that indicate the induction of lambda by UV and the differences
in radiation resistance or lambda sensitives and lambda lysogenics.  There
is a table in here somewhere that has a plot of it looks to be about 5 or 6
lambda lysogenics and in the order of about 8 or 9 lambda sensitives and
of course as you might expect lambda lysogenics are more sensitive as a
rule than the lambda non-lysogenics. And I worked during that fall interval
in this area.  In addition you remember that there had been a set of E.coli
strains isolated which had been tested for mating with K12.  These were
the strains which were called WG strains and I was assigned a couple of
these strains to work with I believe.  As I go through my notebook here
looking at some of these things - I haven't looked at this book in 10 years
I guess at least.  I was assigned I think strain WG 14 and WG 16 and in these
strains we were to isolate auxotrophic mutants and so there are a number of
references to penicillin selections and whether they are mutants or not and
I don't know how far that went.  I think somewhere down the line I had a
few mutants but they were difficult to select because the penicillin 
technique didn't work as well for those strains as it did for K12.  Now in
addition and I don't remember the details on this, it probably had to do
with the study of the "Lwoff effect" that is the induction of prophage by
UV exposure and in that connection I had gotten from Esther several phages. 
She had been studying lysogenicity by several other phages of which I think
there's one called sigma and there was one called - there was another phage
882 and I think there was a third one.  None of these phages grew very well.
I don't find in my notes much of any reference.  I don't think they were
inducible by UV and we were to turn to other things anyhow later on and I
don't recall what became of that.  Well the thing that was important because
I was radiating lambda lysogenics was I had quite a bit of lambda phage on hand
and they were fairly good titered preparations you know in excess of 2-3 X 10
kind of thing and I find in my notes on page 47 and this dated
March 26, 1952 that I did attempt a transduction with lambda to 58-161 on
D(o) media for the purpose apparently of replacing the methionine
requirement of 58-161.  I believe that at that time it was felt that the
biotin requirement of 58-161 had been lost and somewhere else in here there
is a note to the effect that I had done this experiment assuming that the
biotin requirement had been lost.  Anyhow I plated it out 58-161 with 
several amounts of lambda and incubated it for several days.  It was 
discarded about two days later with no colonies appearing on the D(o) 
plates.  That was the first attempt but had nothing to do with the lambda
Gal business.  And then there was a subsequent attempt in the same vein
with W1655 which was a non-lysogenic derivative which came I believe from -
50-161 1655 was a lambda sensitive derivative derived from 58-161 and that was
attempted on again at about the same time March and this time I got a few
minute colonies on the D(o) plates and there is a note on March
31 that I tried the 1655 experiment again, again with no colonies being
produced and so that was set aside.  Regarding the  -  and this is 
followed by quite a number of pages on attempts to isolate mutations -
auxotrophic mutations of those other strains and it occurs to me that
the business of the lambda transduction with gal came about most successfully
or rather a lot of confusion came about during the week that you and
Esther were attending some meeting down at I believe at Rutgers and Norton
Zinder and I were in the lab alone - I think Dotty Gosting was there on
occasion but Norton and I were there essentially by ourselves and in the
course of doing some experiments I asked Norton if anybody had really looked 
at lambda for to see whether it could transduce anything and its my recollec-
tion that Norton said that he thought that Esther had done something in this
area but he didn't know what it was and that in any event it hadn't been
productive and so I said well I've got lots of lambda phage should we just
try it out on everything available.  Remember in those days we had all kinds
media selective media and so I believe my recollection is that Norton and I
agreed we'd try everything possible available and I gave him lambda preps
and we just went up to the shelves and took out all kinds of plates and
mixed lambda with the right kind of recipients that would possibly 
demonstrate transduction and plated them out.  You might ask Norton if he
has any notes of this but this would have been somewhere around according
to my notebook somewhere around April the 20th or 23rd and I see in my
notes that I made a serious effort to do a lambda transduction and 
unfortunately I never wrote  down the things that were negative so I don't
really know which ones we tried any more except that on page 62 of my notes
and its dated April 23rd Wednesday 1952 that I did try a transduction with
W1736.  That was a strain that I had been using with regard to those 
lysogenicity studies with 882 and some of the other prophages that Esther
had given me.  Anyhow I had plated it out and my notes indicate on that
page that I plated it out with on EMB Lac with lambda and I had used 
increasing amounts of lambda, a couple of plates with no lambda then 
plate with .05, .1 and .2.  Then a standard amount of 1736 cells, then
my notes indicate that I looked at the plate on the 24th and there was
no papillae on the 24th and on the 25th with two days a papillae began
to appear and then on the 28th which would be five days later it indicates
that spontaneously there had been produced 32 and 26 papillae whereas with
0.05 mls of lambda prep there were 186 papillae produced; with 0.1 ml of lambda
preparation there were 274 and with 0.2 there were 372 papillae.  And then I
note next to it that at some later date in red pencil had added some ratio
of papillae per lambda plaque on the unit.  Now the confusing thing was
that these were on EMB Lac plates and subsequent that I purified these
papillae by restreaking them on EMB Lac and of course they came out Lac
minus which was very baffling because they had been selected by this Lac
EMB medium and how come they were negative and then I did it again
a couple of times.  Actually this is followed by quite a bit more information
on radiating that HET strain 267 that I'd been studying getting survival 
and induction and things on it for the Lwoff effect.  So I didn't
pay that much attention to the lambda transduction thing with W1736.  But
over on the 28th I had streaked them out on EMB Lac and they came out Lac
minus and then I replicated them to galactose and it says here that in one
case 6 out of 7 were gal+ and 16 out of 17 were Gal+.  Now it's my 
recollection that at this time you had returned and Esther had returned
from the Rutgers meeting and that somewhere in the course of this confusion
about the selection on EMB Lac and they were Lac minus that Esther had made 
a suggestion that I should perhaps look to see how they were with regard
to galactose.  It's my recollection that Esther had done her Ph.D. thesis
on the interaction between Lac and Gal and she'd done a number of things
on Gal and it was a good suggestion.  And I believe that's when we finally
got on to the right track with regard to lambda transduction of the Gal
genes and that would have been in late April of 1952 but it was a long time
before anything was really published on it. My notes thereafter again go
back to referring to radiation of the HET strains and also working on
WG 14 where I'd isolated both the proline and the tryptophane 
requiring mutant.  And this continues on and for some reason which is not
clear to me now there are a number of confusing experiments.  I became
involved with a W112 strain which I believe was an unstable Lac- strain
and that didn't help things at all.  It made things more confusing.  But
anyhow I still continued with the radiation experiments for many pages here
and actually on May 8 I show transduction to W112 Lac- and again I got
a response that was confused.  The papillae that I got were Lac pink
they weren't strong pluses and then some of these appeared within
                same time same day May 8th a transduction to W1736 again
with lambda and it is at this time that it must be that I discussed this
with you because I introduced a control here which I associate with some
conversation with you that is I used boiled lambda prep as a control
because we were concerned about whether the lambda preparation itself was
providing some sort of release of selection and allowed things to grow
up sort of a non-specific sense.  On this date I show that I used lambda
from K12 which had been boiled and non-boiled and then I also and this
preparation gave me papillae.  The boiled lambda gave me 17 and 22 papillae
per plate whereas the non-heated lambda gave me 324 and 345 papillae per
plate which was a significant difference.  On Friday the 9th of May I did
another experiment with W1736 increasing amounts of lambda preparation and
no lambda and I got increasing number of papillae which is almost linear
with the amount of phage added.  I did this both on Gal and on Lac and
again as it shows that the lactose provided some sort of selective thing
but the experiment on the EMB Gal was quite clear cut.  And I noticed on
this date that I had respread some of these papillae and evidently we
were still concerned about the possibility of a selection of the lambda
prep by itself and not the transduction because my notes say that this
finding suggest that papillae on EMB Lac control are different than papillae
on EMB Gal that the Gal transduction effect does not now appear as a release
of negative inhibition against Gal+ clones.  And I note that a few days
later on the 13th of May 1952 that I tried a transduction with lambda
and boiled lambda with regard to the serine-glycine markers the W1678 and
this is on D(o) medium and the results indicate that as of six days
later I got one colony and three colonies on these plates and that there
was not an indication of transduction.

     Now this thing continues and I'm still radiating H267 for survival and
for lambda induction.  I notice on May 15th that I try to do a lambda
transduction of the leucine through the leucine requirement of W1736 which
again came out negative.  I used heated lambda at this time as a control.
But I also noted at this time that in some of the streaks of some of the
Gal papillae it says on page 75 that papillae that I picked from the W1736
transduction on Gal they all grew, they had no other nutritional requirements
that they all appeared Lac- and that there sectoring and again at this
time on the Sunday the 17th I picked from the papillae from the W1736
transduction and this was done on Gal and they were picked to lactose 
and shown to be Lac light negative or very slightly  Lac positive
and they were then replicated to Gal and of the ones that I tested 34 out
of 35 were Gal+.  But again I'm still working with a phage called 882 on
this page and there is still something going on with this W112 strain which
seemed to be contaminated with some kind of phage.  And for some reason
which is not clear in the next few days on like May 20th I'm doing 
experiments with a strain called 1998 which apparently is a lambda lysogenic
derivative of this strain WG28 and again it's a case of looking for the
induction of lambda as a consequence of UV radiation looking for
induction in one of these other coli strains.  And on the 27th of May I did
for reasons which are not clear I irradiated a lambda preparation and used
it as a source of transducing phage for Gal to W1736 and I showed that with
increasing dose of UV going from no radiation to 240 seconds that the
number of papillae increased from somewhere around 200 to something like
3200 with that increasing dose of UV such that irradiating the lambda made
it a better transducing vehicle than non-irradiated lambda.  And I note
also that I tried some transductions in another strain W1662.  By the 28th
of May we had not decided to go full speed on lambda although I did do
an experiment with W811 which is Gal 4-lysogenic and I did get evidence
for transduction there again using irradiated phage and boiled lambda as
a control and I think that  -   but I'm still continuing to do the Lwoff
type experiment.  We hadn't decided yet.  And on the 29th I tried to do 
a transduction with lambda with irradiated lambda with regard to methionine
marker of 58-161.  And yes at that time also we decided to do some
reconstruction experiments by putting Gal+ strains in the presence of a
large background of Gal- and this was done with W1736 again and again I
see that it shows evidence for the increasing numbers of papillae as a
function of lambda concentration.  And it was this stage that we decided
that we had to see if it had something to do with lambda specificity and
so I obtained from somewhere strain W1439 which is a Mal-derivative
I believe of W1436 and it would be lacking lambda receptors and would not
absorb lambda and I did a transduction with it as the recipient using 
heated lambda and even irradiated lambda and my notes for June 1 show
that these exposures of W1439 to lambda and irradiated lambda did not
produce any Gal+ papillae suggesting that lambda was the vector involved
in the formation of the Gal+.  It is here my notes start mentioning 
Gal "transduction" in a couple of places.  And on subsequent pages the
experiment was run on xylose, EMB xylose medium with 1821.  It's my 
recollection that the xylose medium had some selective potential for Gal+.
This is indicated by the fact that there was a large number of papillae
produced on xylose which subsequently must have tested and subsequently
shown to be Gal+. And it must have been about this time around the 1st of 
June in 1952 that we decided not to continue the studies of the UV induction
of lambda and of the radiation resistant differences between lysogenic and
non-lysogenics because I see my notes and I begin to devote most of my time
to Gal transduction with various strrains and included checking the Gal+ to
see if they had been changed for any other markers. We then moved to some other
strains W902 which was a Gal 2- strain and I see that it was done on the
10th of June and again for reasons I don't understand that W112 strain is
involved, I did a cross with W1655 for some reason doesn't tell my why.
But I now begin to see that I worked with W1736 W811 with Gal transductions
and I begin to see in my notes that I have accumulated phage preparations 
and on June 16th of 1952 I received W750 which is a Gal 1-strain so I've now
looked at Gal 2, Gal 4 and now beginning to look at Gal 1 for transduction.
It says I did this experiment back a few days earlier on the 10th of June
I did with Gal 1 and showed that the control Gal 1 strain is a very stable
gave very few spontaneous reversions of Gal and I note that with no phage
I got zero papillae and with 0.10 ml of lambda prep I got 409 which is a very
clear cut difference.  I also see now that perhaps some of the W112 crosses
had to do with the presence LP2R because it looks like there was some
crosses made here to see if LP2R was involved in whether the transduction
would go successfully or not.  But on page 94 which is June 23, 1952 I
used as a control I did a transduction to Gal 1 on EMB Gal using Gal 1
cells and using heated lambda and using lambda derived from Gal 1 and the
results indicate that heated lambda gave only 2 papillae, boiled 12 lambda
gave 405 and lambda derived from Gal 1 itself gave only 2 as
expected.  I see a few days later that we hadn't given up on what kind
of genes lambda could move around. I see the evidence for an experiment
to see if it could transfer streptomycin resistance which again was 
unsuccessful.  Now for the hetergenotic state of the transductions of
lambda I find on page 96 on Tuesday, July 1, 1952 that I had picked the
transductions from the Gal 1 transductions mentioned on page 93 and I
had streaked them out and they had been streaked out, four streakings it
says, and that they were still segregating and stocks were made and these
were now given the label of their origin that is to say 750T902 was a 
transduction clone derived by phage from 902 being applied to 750.  Be it
this time that we really became aware of the fact that they were
heterogenotic because I see further down the page that I had taken a
papillae from a transductions from wildtype to Gal 1 and from wildtype to
Gal 4 and these papillae had been streaked out in the case of Gal 1 five
times and their still mixed after five individual colony selections and
this then now done with a W1736 which I believe is Gal 4 strain also and
they were picked and streaked out.  Now it says three times, three times
and five times and their still segregated.   

     Now in early July I received from Esther W892 I believe it was a
Gal 3 culture and I spent I think another month or so on this culture not
realizing that it was mixed.  It was a mixed culture which confused things.
But I note also that I continued to look at the segregation aspect of the
heterogenotes and seemed like I've now ceased to do the other kinds of
experiments on Lwoff effect and on the radiation things.  And this 
continues until the next number of pages covering up until the end of 1952
had to do with looking at the stability and that sort of thing and whether
they are lambda lysogenic.  These were still from the LFT preparations and
it isn't over until around February early 1953.  I had not bothered to
irradiate any heterogenotes to see what kind of phage they had given.  It's
my recollection that on one occasion I had done this and had got such a
high titered phage preparation that I thought there was something wrong.
Remember in those days, this is before the Millipore era, and we used to
sterilize our phage preparations by adding a few drops of chloroform and
shaking them up.  It's my recollection that I had done this and used this
a particular preparation for transduction and it came up with the amount of
phage plated overwhelmingly plus and so I felt that the thing had not been
sterilized sufficiently or hadn't been sterilized.  With the chloroform
I remember putting additional chloroform in and shaking it all up again and
repeating the thing and finding again that it was still giving such a high
yield of transductions that I thought it was contaminated and so this 
continued and I see that on March 10, 1953 that I have notes stating
transduction with high activity phage and I got tremendous number of
papillae.  This was the phage derived from the - it doesn't give the exact
source here but I believe these were experiments that were taking the
segregants from say a heterogenote made between Gal 2 and Gal 4 and 
attempting to classify them as to what they were 4 or 2 and using I guess LFT
lambda at that stage but I'd taken a - my notes are not clear here but it's my
recollection that I did not use Gal+ heterogenotes as a source of phage
and that I had taken some of the segregants for a heterogenote between
2 and 4 and attempting to classify these had made preps from them such
that the high frequency transducing lambda actually was first picked up
with regard to a segregant from a heterogenote which happened to be
actually itself was a homogenote.  And it gave me very high titered phage
preparations.  I note on March 30, 1953 that I tested a phage prep W892
high powered lambda it says and asking the question is this high powered
DNase susceptible? And so I treated it with DNase for 10 minutes at 37 degrees
centigrade and it indicates that this lambda prep diluted 1 to 100 
gave more than 10  papillae per plate which indicates that it probably had
a titer of about somewhere 10 -10  transducing particles per millileter
which is about the way they ran at that time.  That the transducing particles
so-called lambda DG - that was a term coined by Jean Weigle and Werner Arber
and Kallenberger in Switzerland around 1956 a couple of years after this time
but we knew that some of the lambda particles were defective is actually
contained in the first paper that we wrote where there is a table which
shows that some of the transductants were defective.  Yes in the first 
paper that we wrote on page 152 Table #8 examination of the colonies after
exposure to HFT lysate.  There is a column headed LPR which meant that
they were defective phage particles.  Actually Jean Weigle apologized to me
for not having noted that.  They made such a big thing of the defectiveness
of lambda that he had overlooked that we had said in fact that some of the
lambda transducing particles were defective and that he had overlooked that
particular Table.  There's some other things that relate to this that I
can tell you separately with regard to Allan Campbell's participation in
this  -  End of Side A.    

Side B

    Campbell had a paper to publish which was incorrect and as a consequence
of discussions that he'd had with Weigle I think this was at Cal Tech and 
Weigle has communicated - this would have been sometime in 1956 which is two
or three years after the material we're talking about in my notebook that he
must have communicated to Campbell that Arber, he and Kallenberger had
shown that lambda particles that were doing the transductions were
probably defective and that Campbell changed his whole manuscript to fit
this concept and John Weigle wasn't very much pleased with this.  Okay to
return to my notebook and the interval now is late April, early of May 1953.
I began a serious classification of the Gal- which were segregated from a
heterogenote and I see notes on the back that I made a heterogenote between
Gal 1 and Gal 2 and that I had collected a number of segregants from this
heterogenote and I had classified them by testing them against low titered
lambda preparations from Gal 1 and Gal 2 to classify what they were and
that indicates that there were 18 segregants which were Gal 1 and there
were 5 segregants which were Gal 2.  The source of the phage had been Gal
2.  And then there are indications that I had taken some of these segregants
and also tested them by crossing.  There were available strains that I could
do bacterial crosses with.  And I'm still stumbling around with this HFT
phage which I didn't understand and did some experiments with it to relate
the transduction to lambda I find an experiment on page 199 which is May
16, 1953.  This is an experiment I don't remember at all.  We obtained
somewhere I guess maybe Cal Tech some anti-lambda serum and I tested the
inactivation with this anti-lambda serum.  I tested the inactivation of
placque-forming ability and transducing ability and I find on page 199
that after treatment with anti-lambda serum that I got placque survival
of 43.3% and on the same preparation I got 39.8% survival of the transducing
activity - a suggestion that in fact the transducing agent is lambda.  It was
also about this time - I see the first experiment - that I began irradiating
lambda preps to show - this would be the 18th of May 1953 - that irradiation
of lambda greatly stimulated the transducing activity - I have a graph that's
on page 200A which shows that I irradiated a lambda prep and plated it on
several hosts and got increases in transducing titer of the order of like
50 or 60 fold in this graph.  And this is at a time when the placque forming
ability of the lysate had dropped two decades.  And that page 200B shows a
similar prep that was asssayed on Gal 4 and it was assayed on recipients
which were lambda sensitive, lambda lysogenic and carrying a lambda defective 
prophage.                                                 

     I see by page 202 it appears I now have available HFT lambda  
preparations that could be used for typing Gal 1, Gal 2 and Gal 4 I see
that there is a mention of an HFT Gal 4 on this page.  This is dated June
6, 1953 and this is followed in the next two pages by an attempt to 
transduce not from - to + but from + to - with these new HFT preparations.
That's on June 16, 1953.  I'm now nearing the end of my first volume which
ends on page 218A and these pages between say 180 and 218A have to do with
classifying the segregants from heterogenotes, irrradiating lambda to show
that it increases the efficiency of transduction in a number of experiments.
However as yet I have found no indications that they were tested for 
whether they were defective lambda's or not.  There are all sorts of
experiments in here where I used a lambda, Gal 4 culture which was lambda
defective as a recipient in transductions and it shows that most of the
transductives came out defective because the recipient was defective but
are occasional cases where the transductant came out lysogenic.  On page
216 there's a case one of the transductants came out lysogenic, 28 were
still defective.  This comes to the end of my first volume so I'll have to
stop here and get the second one -         bring it with me to the library.

    There's been an interruption of about a day in this tape.  I'm now 
resuming on June 11, 1986 and I'm starting in Volume 2 of my notes which
begin on page 219.  The starting date is August 26, 1953.

     In the pages that follow here there are a number of experiments which
were done for the purpose of tidying the lambda transduction up that is to
say they are experiments that deal with varying amount of cells per constant
amount of phage, and varying amount of phage vs a constant amount of cells
in order to get linear relationships between the number of transductions
and the dilution of the phage preparation.  And this is then followed in
a bit when I first began to try to grow lambda lytically and on page 227
there is a reference to lambda grown lytically on W518 and evidence
that this lambda did not transduce Gal genes when it was applied to W2175
on EMB Gal.  The titer was very good titered phage 3.3 X 10   -
         .   Then there's another experiment shortly thereafter page 228
was lambda grown on W1485 which also was not active when plated against
three separate strains W750, W518 and W2175.  I then began to study
something of the charactistics of the segregants from heterogenotes and
was surprised to find that on October 6, 1953 that I was beginning to find
some of the Gal minus' that were segregated from transductions were
actually lambda sensitive which was kind of puzzling because we had not
thought much about that.  Thereafter I did a number of these same sort of
things and remained a bit puzzled by the fact that the segregants were
sensitive.  Thats in some cases not every case but in some cases they
were sensitive.  Then on page 241 this is November 8, 1953 I did an 
experiment with HFT lambda such as to get low multiplicities of infection
and I note that my notes say that I obtained some transductions under
these conditions and that of 24 that I tested that one of them of lambda
lysogenic and the other 23 were "LPR" which could mean that they were
lambda defective and this is then followed on note from November 17, 1953
which says in a repeat experiment one unstable plus was obtained.  An
analysis of this plus, 4 examples of it showed that it was lambda resistant
but it was not lysogenic which I take to be the best definition of a lambda
defective.    

     On November 16, 1953, page 244, I note the isolation of W2341 which was
the result of an attempt to put Gal 2- into a Gal+ HFR and it turned out
that W2341 and the notes indicate that it was not sensitive to lambda and
it was not lysogenic when it was tested against W518 and it was sensitive
to lambda virulent.  And so that this was another definition of a 
transduction made by a defective lambda.  Going back a few pages I notice
that on October 26, 1953 the isolation of W2350 which is the first case
of a double Gal- produced as a recombinant from a heterogenote between 
Gal 1 and Gal 2.  And thereafter there are many pages that deal with
quantitation getting linear graphs as a response.  There are also
quite a bit of space to go to collecting Gal minus' from heterogenotes and
classifying this to which allele they were.  And then there is a series
beginning in December of 1953 where I began to make transfers of Gal 
alleles to other strains by means of HFT lambda and then I also began
to isolate some new Gal alleles.
I believe I referred earlier to Table 8 in our first paper on page 152
and I find by looking at my notes that that was an experiment which occurs
on page 254, an experiment which was begun on January 11, 1954 and my notes
indicate at that time I had done a transduction with HFT Gal 2 onto   -
I don't see what the recipient was here but this was the origin of W2866.
Perhaps the stock book would say what that was but anyhow this is a case
where I got three defective transductants vs 23 lambda lysogenic    
transductions.  Also this page shows that I did another experiment with
lytic lambda and this is labelled retest #3 where I applied lytic lambda to
lambda W750, W2281, W2373, W518 and W811 and there were a very small number of
papillae produced in each case and these were streaked out.  The notes say
that the papillae were either all stable or slow pluses again indicating
lytic lambda does not transduce.  In February 13, 1954 I did a double 
transduction here.  I took the Gal 1, Gal 2- produced mentioned earlier
and I applied to it HFT phage from Gal 2 and HFT phage from Gal 4 and
obtained heterogenotes apparently the result of double transduction.  I
guess that was just sort of a fun experiment.  No I'm sorry W2350 is
4-8-, Gal 4- Gal 8- according to the notes written on the margin here.
Again in February 1954 I did an experiment where I got 3% of the cells
that transduced to Gal+.  This was some experiment apparently done in
connection with Esther because it says that Esther's EM analysis in her
book on page 667.  Then in March of 1954, the 25th, there is mention of
an experiment with Tom Nelson with regard to the transmission of the Gal
fragment in crossing.  I don't know exactly what the results of this
experiment was.  During this time I had a great deal of difficulty 
maintaining HFT stocks particularly the homogenotic Gal minus' and 
there is considerable time spent in reisolating strains that were lost.
And then I see in April 1954 I was working on making triple Gal minus'
1, 2 and 4.  Also in April of that year I noticed that I did some
experiments with HFT lambda preps applied to the Mal-  lambda 2
resistant Gal- W902 for example and obtained from this apparently
lambda penetrated the cell in the absence of lambda receptors and I got
some transductants small in number.  We had been concerned because of the
failure to get good wildtype transductants from applications of HFT 1
onto Gal 4 or HFT Gal 4 onto Gal 1.  And then the question was asked and
this was on April 14, 1954, is the complex the heterogenote between 4 and
1 phenotypically plus?  And there is a note that the pluses appear to be
secondary and segregating minus'.  And then I did an experiment at that
time with HFT 1 applied to W518 and got 2 transductants which papillated
and gave off pluses.  The heterogenotic cells were phenotypically negative at
the early stages and in the course of growth apparently recombined to
give Gal pluses.  Again over in June 1954 I see reference to additional
experiments with lytic lambda.  Again as if we were not completely 
convinced that lytic lambda did not transduce Gal genes.

     In July of 1954 I was back working on the quantitative aspects of
HFT phage where I was finding out if HFT Gal 2 was linear on Gal 1 and
Gal 4.   There is a graph showing this response.  Then I see also again
on September 9, 1954 a further examination of W2341 to find out what
its status was with regard to lambda.  It was isolated as a Hf Gal 2-
which turned out to be lambda resistant and Tom Nelson isolated some
lambda sensitive segregants from it.  And there is a question here at
the head of the page that says, is this an indication of its LPR or LPS?
And so it was streaked out and tested and the LPR's those could be lambda 
defectives Gal+ reversions were selected. Those that were Lpr were segregating
minus'on streaking.  The 6 lambda sensitive Gal+ that were picked were 
stable therefore 2341 is shown to be 2-LPS over 2-LPR.  Coming from the
following reaction it is a transduction of the 2-LPR phage into a Gal+
lambda sensitive recipient which then yielded this heterogenote which is now
recombined to become Gal 2- but is a carrier of a defective lambda phage.
There is an interestingg experiment on Sept. 20,1954 on page 288 which is
raising a question about W2344 which is a T1 resistant derivative of 2341
which is the Gal 2- which is carrying a defective prophage (is a homogenote).
And there is a question of testing colonies of 2344 and of the 17 of these
colonies were tested and they were all lambda sensitive and it says
suggestion that only LPS segregants of 2341 can be made V1R.  Then there
is a note that says since according to Cavalli suggestion crossing over
between fragment and chromosome Gal- results in a diploid for V1R and Lac?
I now see that on October 1954 on page 292 that I was examining the 
segregants from a heterogenote which is drawn as being R over S with
regard to lambda and then there is a classification of some 15 or so
segregants from this both with regard to their Gal type the Gal-allele
and also with regard to whether they were lambda lysogenic or lambda 
sensitive or lambda defective.  Interspersed with this there were a
number of experiments that had to do transductions W1924 which was a
Gal 4- strain that carried a defective prophage.  I never really looked
at these experiments. I'm not sure what they show.       

     Over on page 295 November 1954 in another experiment I tried to make
transductions with virulent mutant of lambda and I don't know what the
outcome is.  I have to study this a while before I can figure it out.
In January of 1955 I notice that I'm studying the position effect between
Gal 1 and Gal 6 and that there were heterogenotes that were phenotypically
minus which papillated and then make an extensive analysis of the
segregants that they produced. Then I see the notice with double Gal-
of this experiment as well.  There follow many pages where there are
making various kinds of stocks with the various Gal minus' and HFR and
then over in June of 1955 I began making measurements in a Luria-Delbruck 
kind of experiments on the cross-over rates.  There produced between
certain non-complementing Gal minus'.  And I see that in January 25, 1956
page 390 that I have a section heading Preparation and Stocks for Kaldcar 
NIH for Study of the Biochemistry of the Galactose Fermentation.  And here
I made a number of transductions into a common background which I believe
is 2637 which as I recall was a strain that you gave me for some experiments
that you were doing with the micromanipulator and this was a number of
transductions and then there is a classification of some of the progeny
and it says then go see page 396 and this is where they were first
categorized as a group and they were first given the numbers W3091
through 3097 and W3100 to 3110 and that is February 17, 1956.  However it
didn't stop there. There was some confusion and we started again on March
8th making preparation of the prototrophic F stocks with Gal markers
for the Kaldcar stocks and again there's a table that sets up the strains
and there are actually filter paper pick ups of the some of the 
transduction plates that classified these stocks.  Then in April I began
doing some experiments that had to do with the yields of transducing
particles from induced, UV induced cultures, and I see from information
on one step growth curves which I believe indicated that UV only got
a very small particles for induced lambda.  It has to be in the absence
of helper phage I presume.  And I go over and I find that my last entry 
which is page 421 is dated May 30, 1956 and it was at about that time that
I left Madison.  I arrived here in Denver at the Webb-Waring Lung Institute 
June 20, 1956.    

     That is an overview of my notes verbally.  I'm prepared to send you
whatever you wish from them but perhaps after you've heard what I've
recorded for you, you may want to make a little more selection.  I have
no objections to copying everything for you.

     Aside from that here in Denver everything goes pretty well still.
I'm still working in the lab.  I have a grant in radiation biology
on the oxygen effect which is very promising at the moment and it runs until
November 30th of next year and hopefully with a good performance it will
be renewed.  Otherwise here Helvise is involved herself in cytogenetics.
She works for Childrens Hospital doing cytogenetic of leukemia.  She works
for the Eleanor Roosevelt Institute, that's Ted Puck's empire.  She doesn't 
work for him personally but she works for that group where she does 
cytogenetics on hybrids between human cells and hamster cells.  Otherwise
Margaret - we went to Margaret's commencement the first part of May.  She
finally got her Ph.D. from the University of North Carolina in comparative
literature and now is looking for a job.  She has a great many talents but
the good jobs aren't very frequent so I don't know what she is going to do.
Larry after finishing school here went to Yale and got a Bachelors Degree
in molecular biochemistry and biophysics and he has returned here.  He
was unable to get jobs with some of the companies around here that are in
molecular biology but he has finally obtained a job here as a technician
in the gastroenterology division where he is doing quite well although
we are encouraging him to go back to school which I hope he will do at 
some stage.  I have nothing more to add.  I hope to hear in some kind of
a response to you.  I'm sorry if I have to do this on a tape.  It means
you have to take a hour to hear the whole thing but you can always play
it in the bathroom if nothing else.

     So good luck and thanks.    Larry

         

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