October 10, 1955
Dear Rosalind:
I have spoken to Heinz Fraenkel-Conrat some time ago about sending you some reconstituted TMV, and I hope he has done so by now.  If not, the materials should soon be coming along.
Roger Hart has just found out, by way of a confirmation of the earlier work by H.F.C. and R.C.W., that his partially degraded material (infectivity less than 10% of intact TMV) can be reactivated to almost full infectivity by simple mixture with TMV protein.  This type of reactivation has the advantage that there is no worry about possible contaminating virus in the RNA preparation, a matter about which H.F.C. and R.C.W. have never felt completely sure.  Hart works at higher levels of infectivity where the risk of significant contamination in the protein fraction is negligible, and, of course, he uses no purified RNA.
It will be good to see you in late March.
Regards,
Robley C. Williams