This ELISA kit provides quantitative measurement of soluble CD80 (B7-1) in human serum, plasma, and cell culture supernatants, supporting research into costimulatory signaling and immune checkpoint biology. Because soluble CD80 is shed at low concentrations and fluctuates with immune activation status, detecting it requires an assay calibrated for the picogram-level range encountered in both resting and stimulated conditions.
Detection Range: The 6.25–400 pg/ml range aligns with reported circulating sCD80 levels, which remain in the low picogram range under homeostatic conditions but can rise significantly during autoimmune flares, graft rejection, or tumor immune evasion. Most serum and plasma samples can be assayed neat or with minimal dilution, simplifying workflow.
Sensitivity: At 3.125 pg/ml, the kit detects sCD80 in baseline healthy donor samples and unstimulated dendritic cell or macrophage culture supernatants, where concentrations often fall below 10 pg/ml.
Sample Compatibility: Validation across serum, plasma, and cell culture supernatants enables researchers to correlate ex vivo stimulation assays—such as antigen-presenting cell maturation studies—with patient-derived biofluid measurements within a single platform.
Assay Efficiency: A 50–100 µl sample requirement accommodates limited clinical specimens or primary cell-conditioned media, while the 1–5 hour protocol supports same-day data acquisition across multi-condition experiments.
This kit is directly applicable to studies of immune checkpoint regulation, transplant rejection monitoring, and tumor microenvironment profiling.