Caspase 1 (CASP1) cleaves IL-1 beta between an Asp and an Ala, releasing the mature cytokine which is involved in a variety of inflammatory processes. It also has lots of other function, such as defenses against pathogens, cleaves and activates sterol regulatory element binding proteins (SREBPs), promotes apoptosis. Besides, Interleukin 1 Alpha (IL1a) has been identified as an interactor of CASP1, thus a binding ELISA assay was conducted to detect the interaction of recombinant rat CASP1 and recombinant rat IL1a. Briefly, CASP1 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100uL were then transferred to IL1a-coated microtiter wells and incubated for 2h at 37°C. Wells were washed with PBST and incubated for 1h with anti-CASP1 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody, wells were aspirated and washed 3 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37°C. Finally, add 50μL stop solution to the wells and read at 450nm immediately. The binding activity of of CASP1 and IL1a was shown in Figure 1, and this effect was in a dose dependent manner The binding activity of CASP1 with IL1a.