A rapid, accurate, nonradioactive method for quantitating RNA on agarose gels.

In order to study quantitative gene expression with Northern blots, it is important to have an internal standard that can be used to verify even loading or to correct for uneven loading between lanes. In this study it is shown that two-dimensional quantitation of ethidium bromide-intercalated 28S rRNA fluorescence can be used for such standardization. It was found that the film response of the fluorescence was linear with respect to total loaded RNA in the range of 2.5-12.5 micrograms RNA under the conditions used, after which the linear relationship falls off. This method eliminates the use of radiation for internal standardization of Northern blots.