September 22, 1971

Dr. Edward C. DeLand

Physical Sciences Department
The Rand Corporation

1700 Main Street

Santa Monica, California 90406

Dear Dr. DeLand.

Thank you for your letter of September 15th and for the report
on models of individual blood,

We have goals that are clearly convergent although our approaches
differ in a number of respects. Our primary interest is in qualitative
organic analysis; our principal tools are gass chromatography and mass
spectrometry, under computer management, and we hope to facilitate the
identification of metabolites, as well as environmental toxins, which
may help point to health hazards. The global picture must also include
models of metabolism with which to integrate observable data on the
occurrence of various intermediate products, I am glad to return your
Courtesy with some of our publications, most of which have yet to
demonstrate a bearing on medical problems.

Although our own work is in a somewhat different direction I
am, I think, very well émbued with the importance of the approaches
that your work emphasizes. I have only a limited enthusiasm for purely
empirical approaches to "multi-phasic screening techniques" and the
elaboration of reliable models, along the lines of your work, is an
indispensable basis for their intelligent application.

I am sure you will want to be in touch withMaurice Cullen's group
at Kaiser Permanente in Oakland, which is undoubtedly one of the most
active centers in the country for the collection of multi-phasic patient
data; and on some occasion you might wish to visit here where you would
indeed be most welcome,

Sincerely yours,

Joshua Lederberg
Professor of Genetics
IL/rr

Sucle ued