Assays for Gene Expression

Abstract

The expression of a given gene is initially manifest as an RNA transcript, which is subsequently translated into a protein molecule. That protein molecule may possess characteristics such as antigenicity or bioactivity that enable the experimenter to monitor its production. Described next are the most sensitive, reliable assays currently available for monitoring the presence of specific RNAs, including Northern- and PCR-based methods, as well as methods for monitoring the presence of a given protein, including immunoprecipitation, Western, and immunofluorescence analysis. Also included are the quickest, most sensitive isotopic and non-isotopic detection methods for both specific RNAs and specific proteins. The protein-detection method facilitates the detection of nanogram quantities of proteins in Western blotting experiments with exposure times of but a few seconds. Lastly, procedures for the analysis of post-translational modification of proteins are described.