CTLL-2 Assay

**Semantic type:** Laboratory Procedure

**Definition:** A bioassay used in the detection of interleukin-2 (IL-2) or interleukin-4 (IL-4) in the supernatants of in vitro-stimulated cells. It relies on the IL-2- or IL-4-dependence of a cytotoxic cell line (CTLL-2) for in vitro proliferation, and the measurement of the growth of the these cells is usually determined by tritiated-thymidine incorporation pulsed into the CTLL-2 culture 8-12 hours immediately prior to harvesting the CTLL-2 cells.

**Synonyms:** - Cytotoxic T Lymphocyte Line-2 Assay - IL-2 Assay