Your letter arrived while we were away in Israel on holiday and I am only now catching up on my correspondence,
With regard to Coommasie Blue stain -- you can destain even the protein bands by leaving gels in 40% methanol too long. If
you destain several hours in 40% methanol and then overnight in 7.5% acetic acid you shouldn't lose the protein bands.
If you should lose a protein band, you can restain using the same procedure over again. Please let Koteswar know about this
since he too wrote me about the same problem.
If poly A solutions axe too viscous, dissolving them with, or dialyzing against, dilute Tris, pH 8 helps.
There is a good review discussing IC interactions in Ann. Rev. Biochem. Vol. 36, p. 407, by Felsenfeld and Miles. The stability
of interaction depends on salt concentration, but this is one of the most stable pairs known. We are planning on using this
pair to measure RNase III in E. coli. As soon as we have some experience I'll let you know. This is part of the T7 project.
So far no news on this except that we have phage, bugs etc. growing and can confirm the observation on increased mRNA half-life.
The enzymology starts now.
I received the copy of your Progress Report. Thank you for sending it. You have been busy!
Schlessinger continues to publish short, unsatisfactory papers on RNase V. All assays depend on being able to destroy RNase
II activity to permit detection of RNase V. To this end, they use coli with temperature sensitive RNase II. However, even
the normal RNase II is quite temperature sensitive and you might get away with heating normal typhimurium extracts.
The mention (p. iii of report) about low RNase I in P22 infected cells caught my eye. Do you know any more about it?
On p. VII -- is it the 100-fold purified enzyme that has only 2 bands on gels? That seems odd. It is important to be sure
that the activity coincides with one of the bands.
Please tell Koteswar that I'll answer his letter soon.
Regards to all at the lab. Tell Maharani I finally found a robe for her and will send it this week. A hug for the two little