Invitrogen™ Human CTLA-4 (Soluble) ELISA Kit

Description

The Human Cytotoxic T Lymphocyte associated gene –4 (CTLA-4) ELISA quantitates Hu CTLA-4 in human serum, plasma, amniotic fluid, or cell culture medium. The assay will exclusively recognize both natural and recombinant Hu CTLA-4.

Principle of the method The Human CTLA-4 solid-phase sandwich ELISA (enzyme-linked immunosorbent assay) is designed to measure the amount of the target bound between a matched antibody pair. A target-specific antibody has been pre-coated in the wells of the supplied microplate. Samples, standards, or controls are then added into these wells and bind to the immobilized (capture) antibody. The sandwich is formed by the addition of the second (detector) antibody, a substrate solution is added that reacts with the enzyme-antibody-target complex to produce measurable signal. The intensity of this signal is directly proportional to the concentration of target present in the original specimen.

Rigorous validation Each manufactured lot of this ELISA kit is quality tested for criteria such as sensitivity, specificity, precision, and lot-to-lot consistency. See manual for more information on validation.

CTLA4 (Cytotoxic T-Lymphocyte Antigen 4) is a CD28-family receptor expressed on mainly CD4+ T cells. It binds the same ligands as CD28 (CD80 and CD86 on B cells and dendritic cells), but with higher affinity than CD28. However, in contrast to CD28 which enhances cell function when bound at the same time as the T cell receptor, CTLA4 inhbits the T cell and prevents it from functioning. Intracellular CTLA4 is also found in regulatory T cells and may be important to their function.