A simple, sensitive assay for determining DNA in mononuclear phagocytes and other leukocytes

An assay for determining the DNA content of mononuclear phagocytes is described. The assay is efficient and very sensitive, measuring as little as 1 microgram of DNA. Content of DNA is a linear function of the number of mononuclear phagocytes in the sample. One million murine macrophages contain 10.1 +/- 0.36 microgram of DNA. Consequently, samples of as few as 100,000 macrophages can be accurately quantified to be related to other biochemical analyses.