Immunologic detection of protein antigens after phenol-chloroform denaturation.

The study of gene expression in cells and tissues often begins with phenol-chloroform extraction of the biologic material of interest for the isolation of intact mRNA. In most cases, the proteins denatured by phenol-chloroform are discarded. However, we found that the proteins recovered from phenol-chloroform extractions maintain their antigenicity. Therefore a method was developed for recovering the proteins from phenol-chloroform-denatured extracts that could be saved in lyophilized form until immunologic analysis. In this way, the RNA and the protein analysis can utilize exactly the same sample, and the biologic material can be saved. This is important because often these materials are available only in limited quantities. The method has been used to examine the sea urchin ets-related antigen and sea urchin ets-2 mRNA.