June 1, 1942

Dr. Leland H. Pence

Department of Chemistry

Reed College

Portland, Oregon

Dear Dr. Pence:

I am very pleased that you are planning to go ahead at once with the preparation of the compounds that we need for our work in immunology. The method that I suggest for your obtaining the chemicals that you need is given in the postscript to this letter.

For a general survey of the field of immunochemistry I recommend Marrack's monograph, the title of which is given in a footnote at the beginning of my 1940 paper. I think it might well be available in the library of the University of Oregon Medical School, but you might want to order one for yourself from the British Library of Information, 270 Madison Avenue, New York City. It is not expensive—three shillings in England, and about a dollar, I think, here. Landsteiner's book is also worth having, but it is somewhat harder to understand than Marrack's. The usage of the word hapten is not uniform. Landsteiner introduced the word to refer to a molecule such as a carbohydrate which seemed to be important to the antigenicity of some coupled protein, but which by itself would not produce antibodies when injected into an animal. I use the word to refer either to the molecule or to the group when it is attached to a larger molecule. Sometimes I refer to the group as a haptenic group.

I think that your experiment of taking an antibody and turning it into another antibody in the test tube would be worth carrying out. The job of obtaining purified antibody is somewhat troublesome, so that we shall probably not try this experiment for some time.

Sincerely yours.

Linus Pauling

LP:jr

P.S. I think that the easiest way would be for you to order the chemicals that you need through Reed College, which would then bill us for payment. If you would let me know the approximate amount, I shall put in a requisition and an order would be sent to the Reed College Comptroller.