A new method of measuring histamine within single cells using a microspectrophotofluorimeter

Methods of measuring histamine from large numbers of cells involve inaccuracies due to the difficulty of isolating a pure cell population without damage to the cells. A new method of measuring histamine within single cells by a microspectrophotofluorimetric method has been developed. Calibration of the microspectrophotofluorimeter used o-phtalaldehyde-conjugated-histamine absorbed to Sephadex particles. The concentration of histamine within single rat mast cells was measured and compared with the theoretical values obtained from measuring histamine released from large cell samples.