March 2, 1965

Dr. Lazarus Astrachan

Department of Microbtology

Western Reserve University

School of Medicine

Cleveland 6, Ohio ‘

Dear Dr. Astrachan:

Your letter was turned over to me and I am ashamed not to have
answered more speedily.

a stated in my paper in 1960, our yr 8 episomes will not give the
Lp*/Lp™ heterogenotes; Jacob reports one that does and I believe

he called it C24-23. He sent it to me some years ago, but I was
unable to demonstrate its genotype. Perhaps you will have better
luck. We have not done many experiments involving T4rII. I suggest
that S. Benzer would be your most knowledgeable source for unpublished
experiments in this line.

We are sending W 4520 (carries yr 8) and W 3747 F 13).

Sincerely yours,

Esther M. Lederberg, Ph.D.
Research Geneticist

EML: as