Joshua Lederberg Madieon, Wisconsin May 14, 1956 op. Joserh Lein Brietol Laboratories Inc. Syracuse, New York mar Joat IT am very sorry that ny last mesnage should have been mtilated. If suspose I shall Just have te de wore careful in my aailing oreeedure. f[ will de tae best I ean to recacture the main pointe that vere included in that tranenieston. You may be iaoterested, by the way, that the resord has = coed desl more fidelity then ie soselble te cacture by means ef tha very onal) speaker in these éietachone sachines and you can get very reaveatable resulte by claying them to any audio ty-e of equipment. I doen't know how much of a high-fi fon you are, Ine, bet I wes interested to hear how life-like « tranemiesion can be ectten. This cartieuler recording nacnena to be ande through ay own micrechone and seplifier and I'11 be interested te learn «hat your seerstary saye avout the relative intelligibility of ay recording. ¥iret of all, you will by now heve received o set of three Fla™ and two varelyzeé atraine of Selaonslla. Sxeuse me, there will be three of each according te my notes. Thien is orebebly sore than is worthwhile testing in eny one bunch but you moy find thet some of the quiturss are sore or lese wuiteble then others. I have not caid very close attention to several of there ounltures recently and therefore you should subject thea to single eclony ourifieation and tenting before doing anything more with them. You will be able to ase for yourself uhioh of the cultures is sufficiently stable for ertimal use under your conditions, another considerstion ie that 37666 and 5W71157 cerry Fla” factore which are closely linked to one enethar and these may therefore conceivably resresent mors closely related chyslologiaal cefecte than {n reintion to 5W1153. ©e Kave no information of the genetic linkare relationsnic of tha varalyred mutants exce:t that 211 six of the cultures are distinet from one another. Therefore it will be important ta leok out for tranedueticnal effecte in your exceriments as well as ochysiolecices!] resterstion and function. Thie remark te sapseially nertinent if you are known to uce mixed cultures in coing multicle sereening. Otherwise I do not anticiszate that you will haves any difficulty altheugh, frankly, I will be rather satoniened 1f you can find the meaning of this deatroying effect in theses cases, thet is to sey, which represent 2 sore then ordinary saeeomelishment and therefore ong whose success can hardly be oredicted., On the other hand, the vessibility of finding agents whieh will inhibit Flezgella formation or function ie much sore pleusible and I will therefore be waiting te heer of some voaitive results of your eralininary trials on toat nystem. I heve been waiting te hear frow you with regard to « suitable lucite ce3] for some oreliainary axcerimente on chenotaxie, but tesawhilea I 44d a few more triale myeelf and hove been rather puseled te be unable te reyroduee the chenosensa in a tloeed gliasea tubs. I don't xnow exactly vhat's behind thie end 1t might tars sone more looking st. dorever, the follewing deeiga in eomething thet you can calekly and eimely do for yourself, elthoughs ite mein drawback is that 1¢ does net lend iteelf very well te quantitative oroecedure. I'we hean using the following technique: On a clean, ordinary glese slide, add e ee or two of sinersl o41l from » cropper or cleans bettle until] the slide is more or lese uniformly coated. Then with a for J. Lein - Be Hay 1b, 1956 Srawnout, fine, capillary tube place a sm.il crop, about 3 or & mm in dtamster at sot, en the wirface of the glase under the mineral ofl. The cultur« should adhere te the glass anc spread out under the sil enclosing it. Thie constitutes 2 zrimitive ofl chamber, If you use a very actively rotile Jelmonella oulture, you will then get on interesting effect 1f you touch the sedge of « drov with e micre-pinette or 4 needle carrying s enall amount of « eolution of shenol of say 9.1% concentration. ‘%ithin 5 minutes many of the motile celle will have micrated away from the coint of centect of the shenol and have collected on the opposite side of the droo. Tale ia the banic chesotazie resvonee that I've discussed with you and it veuld be, of course, very intereating to see if tnere are chemicals which modify the “ateric ability” of the wcotile bacterin. It might be helpful to usa a solution of shenol alrendy wade up with bacteria in order te avoid any possible confusion of migration with dilution of the érop with a clear added solution. The exceriueat I have just cnoted you ie just about #1) I am going to with this particular chesotaxia eyatem and I wish I understood why {8 dose not give nearly so startling « sicture when the same experiment is done in eavilleary tubes. inring the inst several weeks, Job wright svent some time playing around with the red, srgininelesa mutants which he finally cot from Hereche!] Roman out in Seattle. From our experlenee, we would both say thet this is not « very satisfactory method of screening for petit-oredueing compounds. The accumulation of red ciement epoarentiy has a negative seleative effect on the cuituras so that they are contiaucusly aequmuleting large mumbers of various genstic kinds of light variante. These would be of very considerable trouble. It is possible to use this vrecedure for demonstrating effeets of compounda like Aerifiavin bat on the whole I think you will heaves « wuch simpler crecedure to use ordinary plating methods on tne wild tyve cultures and ralying on colony size ae your final sereeniug effect. This is not at all diffieult to co and slmoat anyone of the large mumber of steek diploid yeast strains should be onite eompetent for thie experiment. Of course you have the adwantaze of being able to sretest the system by the use of Acrifiavin. Another comeent thet I had emphasised in the record was a punctuation of ay erevious remark abeut the plausibility aa desirability of leoking for on anti-aincose, There hes deen a little work on screening for anti-livelytie agentes for use in the contre] of dente! carries but none of it seems to amount te very much. On the other yaad, there anvears to heave been ne fundamente!] study on the wechaniem of setion of hiorizin, « compound whieh wee much used in the 1920s end 19368 because of ite ececific effect in sreventing the reanl reabeorction of giucose. The ease compound has been noticed to have an imhibitory effect on the abeorstion of glucose from the ent and it mizht be that this would be a starting point for « rational avpraach in eeouring en desireable cempound. The irrations] approach {es of courses equally desirable, nenely, thas sereening of your verious antibiotic filtrates for aetivity ef thie kind. Gms of the first questions one weuld want te know is whether there ia any micredlolosiesl ayaten in waich an anti-glucese effect of general utility could be detected and for this curpeee it would seem to me worthwhile at least te do sowe preliminsry sxveriments »ith Shlorisin on one or another mieroorgeniam. If you can aive se some idea where to get hold of the stuff, I would ewen be interested to tere a quick leok at 1t mynelf, aa I do not know of any literature on sicroblelogies] setivity of this s«liucoside. vhather or not the compound works on Recheriehia coli, it shoul: slso be tried on ‘roterona and sigee, for example Tetrehymens and Euglena, to determine whether it has « dietinctive “hyeielogicn} effect there and I can very well envisece (A) that thera will be g@i\ucoside oceurring in Actinomycetes filtrates if it nae interesting anetivity elong these lines and (B) thnt with suitable modifleations “hlorizin-like compounds micht be of sonsiderabie clinics] importanes. fo: J. Lein -3- May 14, 1956 In m previous letter I mentioned a rather obvious kind of design by which sati-glucese activity might be cleked up with Zacherichia geli. 1 would revest apeia that the most likely agente for such nativity would be found in synthetic mo Mfieatione of the naturnl series, Again, auch compounds are hy no meens excestional es Agtinonycete vroducte. I taink I aight aleo have mentioned to you thet or. Bradley will be going to the University of Minnasotea starting thia fall in the department of Medicel Mioreoblology. He expects to continue his studies on the genetics of Actinomycetes, *ontecorvo was visiting Madison last week end as you >robably "now will be spending the summer at Cold Spring Harber Just in ease you might be interested in trying to maze contact with him yourself, Ponty gave us a very complete necount of the genetic studies with Asvergillue ami Penteilifum and there 1s ho Teneon in the world why one can't go ahead with a comorshensive genetic analysie and bresdice crozren if only there vere something wortawhile to be fotten from 16 with theses oarticulsr selcs, 4g you may already have noticed, there is o paver in tae leet iseue of the de Ganetal Aisreblolegy by jermonti which conceras tha genetics of the effect on vented] iin rredugtion. Although all of the sutants which Sernmonti describes nere acoesr tea Anve heen allelic, I doubt thet he hed really covered the situetion counletely. \8 beat as [ eam reesli now, I do not heve any additions] euggertions at the instant for microbial teet syatens but I suscect you alrsady have about ag much as yon woulc gare to handle anyhow. It seems to me 1 did have sone fancies with regerd to eystene worth testing on mammals but thay seem to elude ne for ths moment cas in any case are perhave not too sertinant te our immediate task. The moat dramatic of those perhace has to do with the consibility of facilitating homo-grafting, a point which wea excited, at least sartly, by « recent note in HaTuRy concerning success in imolonting sart of the lyechoidal system of a rat late a souse that hed vreviously been treated with Keraya, Thie te vert of « much larger cuestion of accuired taleranes to trans- clanteation and it would tale auite a while te #0 inte it here, sevecially ae I den't know vhether thers {e auch peint in bringing it uo with you new, I would urce thet you and your colleagues give thin carticulear eres very careful scrutiny, at leaet in ay own ovlnion it is one of the more vromising openings for drastic changes in aedies! technique, T had in mind the vague possibility: that it mieht be vossible te discovar agants vhich would seratch the scecifie antibody reaction to tranenlant Lome enough that (2) these could becons establianed end (b) that they could in turn inguce some tyre of acouired tolernnee on the cart of the host. Somes time vhen votre together I'é like to go inte thie in more detail with you, cerhage alec with anyone alee ta your organization who would care to listen. As cart of this story it avena to me thet it would be quite worthwhile even right now leoking for agente which can nocify the action ef comrclement on aynthesized celle. Of course it would be a Very ainris test based on the -revention of hemolysie, or if you had te stick to a microbial] syatem on the erevention of beeterialyeis by iamune serue vlus cemnlement. “oseibly slong releted linea you might find that antibedy reactions ageinst crctozon cella will aore closely simulate the effect of antibodies against mammalian cella in tranapiant enc theses mtent therefore be of aeniyatant value. I think in Drevieng diseuasiona we had already dieenesed auch “nyelolorion]