Quantification of DNA binding to cell-surfaces by flow cytometry

DNA binding to cell-surfaces has been documented in several studies. The in teraction of DNA with cells has been shown to have therapeutic potential as a non-viral form of gene delivery and DNA vaccination. Recently, bacterial DNA binding and internalization has been demonstrated in some cells to tri gger secretion of cytokines and cell activation. Previous studies to quanti fy DNA. binding to cells have used radiolabeled DNA. Here we report a non-r adioactive assay for quantification of cell-surface DNA binding based on th e isoparametric analysis of flow cytometric data as described by Chatelier et al., Embo J., 5 (1986) 1181. This assay has the advantage over previousl y used procedures in not employing radioactive material and being able to d iscriminate viable from non-viable cells that bind DNA. With the importance of understanding the interaction of DNA with cells, this assay may have ap plication for the identification and characterization of reagents designed to either enhance or inhibit DNA binding to cells. (C) 2000 Elsevier Scienc e B.V. All rights reserved.