INCREASED SENSITIVITY OF AUTORADIOGRAPHY AND FLUOROGRAPHY BY MEMBRANEBLOTTING

Tile detection of low amounts of H-3-, C-14- or S-35-labeled compounds can be difficult with x-ray films. Here we report the benefits of blo tting labeled molecules that have been electrophoretically separated t o a membrane prior to autoradiographic or fluorgraphic detection. Blot ting allows a reduction, by a factor of 5-10, in exposure times compar ed with dried gels. When combined with a rapid and safe alternative to the impregnation of blots with liquid scintillant, a further 3-fold t o 5-fold increase in sensitivity is achieved. Bands containing as low as 1 Bq C-14 or 100 to 10(3) Bq H-3 could be detected after 24 hours o f exposure. This enhancement in sensitivity may lead to new applicatio ns of H-3 and C-14.