The JAM Test: An Assay of Cell Death

Abstract

Cytotoxic T lymphocytes (CTL) appear to have at least two different ways of killing their targets: they drill holes in the target cell membrane, and they can also trigger the targets to commit suicide. For 30 years, ⁵¹Cr-release has been a reasonably efficient and useful method to measure membrane disintegration, but until very recently, the assessment of target cell suicide has been a slow, laborious, and inefficient process. Here I describe the JAM Test (Matzinger, 1991) a method that measures the DNA fragmentation that accompanies cell suicide. As a general measure of apoptosis, it is fast, quantitative, and easy to do. As a method for measuring the activity of CTL, it surpasses ⁵¹Cr release in several different ways. It is faster, more sensitive, more convenient, safer, more flexible, and cheaper. Its main disadvantage is that the targets must be in growth phase.