Overestimates of the size of poly(A) segments. |
| |
Authors: | A T Burness I U Pardoe N O Goldstein |
| |
Affiliation: | Memorial Sloan-Kettering Cancer Center New York, N. Y. 10021, USA |
| |
Abstract: | Poly(A) molecules containing on average 25, 45 and 90 nucleotide residues are all eluted from DEAE-Sephadex in the presence of 7 M urea by approximately the same NaCl concentration which is higher than that required to elute 4 S and 5 S RNA. The same poly(A) molecules have electrophoretic mobilities on 12% polyacrylamide gels which are proportional to the logarithm of the number of nucleotide residues they contain but not to the number found in 4 S and 5 S RNA, even after denaturation of the RNA and performing electrophoresis in the presence of 2.2 M formaldehyde. As a result, many reported estimates of poly(A) size derived from such techniques are probably too large and need re-evaluation. Corrections are suggested for the use of 4 S and 5 S RNA as molecular weight markers for electrophoresis on 12% polyacrylamide gels. |
| |
Keywords: | To whom inquiries should be addressed |
本文献已被 ScienceDirect 等数据库收录! |