Dear Josh, We find a difference, and a considerable one, in the amount of light reactivation we get between 58-161 and w-1 . We can inactivate W-1 by 5 x 10 to the 4th with UV and reactivated back to 50% original titer [?]. But 5E-161 won't come back up very far. So we want to check K-12 to see how it acts, and also 58 which is presumably B-. We would like a slant of 58 if you can spare it. The above is only one expt and we'll check it upon return from Indiana. If true, it is indeed curious. We finally got a home phone--Midway 3--1959. As soon as we know when we can come up I'll write. I'm going home for Pesach. Aaron