Determination of radioactivity in biological material

The two major counting techniques in use in most laboratories today are those utilizing liquid or crystal scintillation counters. A discussion of liquid scintillation counting is inextricably linked with the problems of sample preparation and both are emphasized in this chapter. Radiochromatography and autoradiography are also discussed. Chromatography is one of the most important techniques for the separation of chemical compounds from biological material. Most of the detection mechanisms applicable to radiochromatography use x-ray film, a β-particle detector, or a luminescence detector. In biological autoradiography, labeled substances in the organism, tissue, or cell, are made visible by preparing thin sections and exposing them to a suitable photographic film. Light and electron microscope autoradiography were also discussed. 12 figures, 6 tables