Studies in histochemistry

Abstract

The micro method is particularly suitable for multiple analyses of microgram samples of biological material, and it can be employed for determinations on microtome sections of tissue, or other such morphologically defined samples, as well as on microliter volumes of body fluids, i. e., for m[mu]g amounts of histamine, with a sensitivity of 0.1 m[mu]g. An investigation of certain reagents and steps in the procedure was made to arrive at optimal analytical conditions. A linear relationship is maintained between fluorescence and concentration of histamine over the range used (2-8 m[mu]g/100 [mu]l sample). Precision of the macro and micro analyses are essentially the same; the latter gave relative standard deviations of 5.3, 3.5, and 2.7% for samples of tissue, blood plasma, and a histamine standard (5 m[mu]g), respectively. Recovery of histamine added to stomach homogenate was 97%.