Leukocyte migration test in a modified agarose medium.

The medium used for the leukocyte migration test contained 1% agarose, 0.003 M HEPES, TC medium 199, and 10% horse serum. The pH was adjusted to 7.3 with 2 N NaOH. The leukocyte migration test in this medium correlated with the intradermal test in 36 subjects when PPD was used as antigen, and the results were comparable to those of the reference technic. Addition of HEPES to the original medium enables the test to be performed in a standard incubator.