Biological activity of mRNA immobilized on nitrocellulose in NaI

In 12.2 molal NaI and at 25 degrees C or below, mRNA bound to nitrocellulose while DNA and rRNA did not. Neither the poly(A) tract nor the cap were required for binding. The immobilized RNA could be translated, reverse transcribed, hybridized with radioactive probes, or released for further manipulation. mRNA was efficiently transferred from polyacrylamide to nitrocellulose in NaI. Baking was not required to fix NaI-immobilized mRNA to nitrocellulose. When cells dissolved in 12.2 molal NaI were filtered through nitrocellulose, mRNA became selectively bound (quickblot). The quick-blot system utilizing protease and detergents to prepare cells for NaI solubilization was especially suitable in quantitative, rapid screening of cells for expression of specific genes. Expression of highly repeated DNA sequences was detected in human leukemia cells.