A silver staining method for single-cell gel assay

The single-cell gel assay (comet assay) is a very useful microelectrophoret ic technique for evaluation of DNA damage and repair in individual cells. U sually, the comets are visualized and evaluated with fluorescent DNA stains . This staining requires specific equipment (e.g., a high-quality fluoresce nce microscope), the slides must be analyzed immediately, and they cannot b e stored for long periods of time. Here we describe, using human lymphocyte s, some modifications of the silver staining for comets that significantly increase the sensitivity/reproducibility of the assay. This silver staining was compared with fluorescence staining and commercial silver stains.