Many molecules of biological significance function at very low levels and are difficult to detect with the standard staining procedures for flow cytometric analysis. This unit describes a technology for cell staining that enhances the specific fluorescence signal by as much as 100-fold. The system is based on the enzyme-catalyzed deposition of a tagged molecule. Enzymatic amplification staining is qualitatively different from the inclusion of additional layers of binding molecules because background fluorescence levels are not increased along with the specific signal. The technique is compatible with multicolor staining. An alternate protocol explains the performance of multiple amplifications on the same cell population by adding a peroxide incubation.