Factors determining spontaneous histamine release from human basophils purified with Percoll gradients and Dynabeads.

Identification of factors influencing histamine release from purified and cultured basophil leukocytes is important for proper interpretation of results obtained on histamine release. This paper describes factors that influence spontaneous histamine secretion from human basophil leukocytes purified on Percoll gradients, followed by negative selection with Dynabeads. Anti-IgE and recombinant human interleukin-3 were used as model stimulants, and the purified basophil leukocytes were stimulated for 10 min and 6 h. The effect of the following conditions was examined: Percoll temperature, cell-suspension density, and serum in the media. The results showed that low Percoll temperature, high cell-suspension density, and the presence of serum in the media decreased spontaneous histamine release and increased maximal net histamine release upon stimulation.