A simple fluorimetric microassay for DNA in hair follicles or fractions of hair follicles.

Human hair follicles may be useful for determining individual differences in the metabolism of polycyclic aromatic hydrocarbons in epithelial tissues. for quantitative measurements of carcinogen metabolism, determination of the amount of DNA in the hair follicles is necessary in order to correct for individual size variation. A simple method for DNa determination in hair follicles is described, based on the use of a hypotonic pronase solution to solubilise DNA which is then available for complex formation with mithramycin or 4,6-diamidino-2-phenylindole. 2HCI (DAPI). The mithramycin method permits the measurement of DNA in a small number of hair follicles, while the DAPI method is sensitive for as little as one single bulb.