THE UNIVERSITY OF WISCONSIN

THE MEDICAL SCHOOL

   MADISON 6

   ALPINE 6-6811

VCARDLE MEMORIAL LABORATORY

FOR CANCER RESEARCH

Play 18, 1960

Dr. Arthur Kornberg
Department Biochemistry
Stanford University
Stanford, California

Dear Arthur :

        In an earlier letter you suggested that I modify my
DNA Model Kit so as to separate the double strand into single
strands .

1 finally thought of a simple way to do this utilizing

the connectors I use to plug in my loudspeakers at various
points in my home. These connectors are k321 Moseley 300 ohm
polarized plugs available from any electronics distributor for
about 10 cents per plug. They can be cemented to the colored
nucleotide pairs using polystyrene cement. By using polarized
connectors it is possible to completely code the pairs so that
a prong = NH and a hole is a = o or -N=. By setting the
connectors l/4 inch over the midline for purines and l/4 inch
back of the midline for pyrimidines the coding can be complete.
Moreover the pre-existing color code provides extra insurance
for proper coding,

I am enclosing 4 pairs for your examination. Please

use a screw-driver to separate the nucleotides if they stick at
first. I also enclose a template that was used to mark the
pairs so they could be properly cut into mononucleotides.

Do you think a supplemental sheet of directions would

be appreciated by users of the Kit?

     Please note that the nucleotides will now be strung on
two wires using the holes I had drilled in the plugs, and you
can now have a double strand opened at either or both ends, with
new strands forming on the opened parts.

With best wishes,

Sinc ere9 yours,

VRP: sek
encls .

Van R. Potter
Professor of Oncology