The Mouse Platelet Factor 4 (PF4) ELISA Kit allows for the detection and quantification of PF4 in mouse serum, plasma, or tissue homogenates. This kit has high sensitivity, excellent specificity, precision less than 10%, high recovery, good linearity, and consistency between batches. It employs the sandwich ELISA mechanism and enzyme-substrate chromogenic reaction to achieve the detection. The solution color develops in proportion to the amount of PF4 in the sample, and the color intensity can be measured at 450 nm via a microplate reader.

PF4 is a positively charged tetramer belonging to the CXC chemokine family. It is released from the alpha-granules of activated platelets. PF4 inhibits local antithrombin III activity by binding with high affinity to heparin-like molecules thus promoting coagulation. It also participates in many other biological processes, including promoting the survival of hematopoietic stem cells and suppressing the proliferation of endothelial cells and fibroblasts. PF4 has recently demonstrated to form stable heterodimers with CCL5, leading to a synergistically amplified ability to recruit monocytes. In the terms of inflammation, PF4 promotes the adherence of neutrophils onto endothelial cells, facilitates neutrophil exocytosis, and supports the generation of reactive oxygen species and other pro-inflammatory cytokines from monocytes to maintain the immune response. The binding of pathogenic antibodies to PF4/heparin complex and subsequent activation of cellular FcγRIIA on platelets and monocytes, resulting in life-threatening thrombosis that causes heparin-induced thrombocytopenia (HIT).