Quantitation of the ras gene product in leukemic blast cells using enzymatic staining

Few studies have focused on the significance of ras protein levels in human malignancy, in part because of the inherent difficulty in quantitation of the ras gene product. We have developed a method for the enzymatic determination of the ras gene product and have used this method for the quantitation of ras gene product levels in 19 patients with acute leukemia. This technique provides a practical means to assess p21 expression in leukemic cells ex vivo while avoiding the use of radioactive reagents. In addition, the mobility of the ras species of interest is determined. This assay should be easily modified for the use of other antibodies such as those reported to be specific for various ras species (i.e., H-, K- and N-ras), for specific ras mutations or for other nonras proteins. Because of the use of electrophoresis prior to quantitation of protein, the antibody used does not need to possess high specificity for the protein of interest.