The behaviour of nucleic acids in membrane chromatography and electrophoresis on nitrocellulose filters

Abstract

Nitrocellulose membrane filters of various types, both intact or impregnated with Tween or serum albumin, were used as carrier material for small-scale chromatography and electrophoresis of native and denatured DNA, RNA and proteins. DNA isolated from calf thymus, and from B. subtilis, total RNA from chick myeloblasts and human serum albumin and their mixtures, in various binary combinations, served as model samples in the experiments. Horizontal chromatography and electrophoresis of 0.5–2 μg/μl samples was completed within 1–30 min on 3–4 cm long strips in citrate, veronal or acetate buffers pH 7, 8.6 or 4.5. Nucleic acids were stained with toluidine blue, proteins with nigrosin. Characteristic behaviour of different samples under different conditions is described and optimal conditions are found for the separation of most substances under study. In general the model substances to be separated either remained at or moved from the start in single spots. However, the sieving effect of small-pore membranes permitted the convenient detection of the presence of three components of total RNA by electrophoresis. The micromethod also appears to extend the applicability of membrane chromatography and electrophoresis on nitrocellulose filters into the field of nucleic acids, especially where rapid information and simple characterization of minute samples is needed.