Description
Chloramphenicol acetyltransferase (CAT), encoded by a bacterial drug-resistance gene, inactivates chloramphenicol by acetylating the drug at one or both of its two hydroxyl groups (1). This gene is not found in eukaryotes, and therefore eukaryotic cells contain no background of CAT activity. The CAT Enzyme Assay System with Reporter Lysis Buffer(a) offers two alternative methods for monitoring CAT enzyme activity in transfected cells: liquid scintillation counting (LSC) and thin layer chromatography (TLC) (2,3). Either the LSC or TLC assays can be performed using the same cell extract. The TLC-based assay (1) is less sensitive and more time-consuming to perform than the LSC assay but is useful as a visual confirmation of assay results. The resolved TLC reaction products are detected by autoradiography or phosphorimaging analysis.