12th August, 1970. Dear Maxine, Thank you very much for your letter dated July 23. We have just now received rubber stoppers and Coomasie blue. It took more than two months to have those released from the Customs. By the way we find that Koteswar's P22-specific lysozyme gives a single band but the Coomasie blue stain (done according to permanent method of staining) disappears during destaining. Have you any idea why this could be? Though we purified PNPase from freshly grown lysodiekticus it was of no use to us as 280/260 ratio indicated the presence of considerable amount of nucleic acid. We have reverted back to dried powder. Actually we have prepared large amount of poly A with this enzyme. This poly A preparation became highly viscous and created some problem during the assay of crude extracts. However, with fractions of RNases there is no problem. We have now started to characterize the other peaks from the DEAE cellulose column. We have some poly I and poly C in our stock. Please let me know the optimal conditions under which they have maximum secondary interaction. We have also started to look for DNases in S.typhimurium extracts with the object of detecting phage-specific DNases. One of the other object is to detect ATP-dependent DNase (the recombination enzyme). Yes, I have received the catalogues from Amicon and Sartorius. Actually I have ordered for some collodion bags from Sartorius. Koteswar has been able to concentrate his enzyme considerably by ion exchange column and sucrose method. So there is no need of sending the collodion bags. Amal is back to work. I shall anxiously wait for your T7 results, may be we can look for the same in P22 system. Swell Champe (with Mrs. Champe) and Myron Levine (with Mrs. Levine and daughter) visited us recently. So we had busy and pleasant time. I don't know whether you are back from the holidays. I shall anxiously wait for the reply. Maharani joins with me in sending our best personal regards to Dan and you and love to the kids, Sincerely yours, (D. P. Burma) Prof. & Head of the Dept.