Spleen Tyrosine Kinase (SYK) is a member of the SYK family of tyrosine kinases. These non-receptor cytoplasmic tyrosine kinases share a characteristic dual SH2 domain separated by a linker domain. Within B and T cells respectively, SYK and Zap-70 transmit signals from the B-Cell receptor and T-Cell receptor. SYK plays a similar role in transmitting signals from a variety of cell surface receptors including CD74, Fc Receptor, and integrins. Besides, Sialic Acid Binding Ig Like Lectin 1 (SIGLEC2) has been identified as an interactor of SYK, thus a binding ELISA assay was conducted to detect the interaction of recombinant human SYK and recombinant human SIGLEC2. Briefly, SYK were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100µL were then transferred to SIGLEC2-coated microtiter wells and incubated for 2h at 37°C. Wells were washed with PBST and incubated for 1h with anti-SYK 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 SYK and SIGLEC2 was shown in Figure 1, and this effect was in a dose dependent manner.