Accession Number : ADA317703

Title :   The Quantitative Determination of C 14 Activity in Biological Systems by Direct Plating.

Corporate Author : TECHNICAL INFORMATION SERVICE (AEC) OAK RIDGE TN

Personal Author(s) : Hogness, John R. ; Roth, Lloyd J. ; Leifer, Edgar ; Langham, Wright

PDF Url : ADA317703

Report Date : 01 APR 1948

Pagination or Media Count : 4

Abstract : With the increased use of 014 tagged compounds in biological tracer studies a method for direct and rapid quantitative determination of radioactivity in biological fluids becomes important. One satisfactory but tedious method involves combustion of the organic material in such fluids as blood, plasma, and urine, collection of the CO2 and the precipitation on suitable plates as BaCO3, according to the method described by Yankwich.1 This method implies that the 014 containing com pound under study be similarly assayed by combustion and counting as BaCO3. A more rapid method involves the direct plating of aliquots of the biological fluids themselves onto suitable counting plates and subsequent determination of radioactivity with a thin mica window (Geiger Mueller) tube. The latter method has been used in some of our studies of the metabolism of nicotinic acid and related compounds. It became apparent, however, that for valid interpretation of the measured activity obtained in this manner, suitable calibration is essential.

Descriptors :   *RADIOACTIVITY, *CALIBRATION, *URINE, *TRACER STUDIES, CALCIUM, QUANTITATIVE ANALYSIS, BIOLOGY, COUNTING METHODS, METABOLISM, COMBUSTION, PRECIPITATION, PLATES, ORGANIC MATERIALS, WINDOWS, FLUIDS, THINNESS, COLLECTION, DETERMINATION, BLOOD, PLATING, BLOOD PLASMA, MICA, NICOTINIC ACID.

Subject Categories : Anatomy and Physiology
      Radiobiology
      Radiation and Nuclear Chemistry
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE