A new method for detecting histamine release

Abstract

Glass microfibres have been found to bind histamine with high affinity and selectivity. A new test for measuring basophil hisamine release has been developed using the glass microfibres as a solid phase. Glass microfibres are crushed and fixed to the bottom of microtitre plates with a water-soluble glue. Histamine release is performed in the glass microfibre-prepared microtitre plates by challenging 100 μl washed blood with 20 μl antigen per well for 90 min at 37°C. Released histamine is bound with high affinity to the glass microfibres, since 90% of histamine in the solution is adsorbed to the fibres. After incubation the microtitre plate is washed with H₂O to remove cells and interfering substances. Fibre-bound histamine is detected by the fluorometrico-phthaldialdehyde method. The sensitivity of the assay is 0.63 ng histamine, 2 HCl and the histamine standard curve is linear up to at least 5 ng histamine, 2 HCl. Optimal conditions for the new assay are described. After challenge with anti-Ige a comparison with the conventional histamine release from Ficoll-Hypaque-isolated leukocytes showed almost identical results.