The Human Perforin ELISA is to be used for the in-vitro quantitative determination of Perforin in supernatant, buffered solutions. The assay will recognize natural Perforin. Note for serum & plasma quantification: high and non-linear detection level is found in human serum and plasma samples. The high signal appears not dependent to the antibody pairs but probably to the matrix and/or Perforin interaction with other molecules. Consequently serum and plasma quantification is under the scientist's responsibility and specific investigations. Remark: no detection signal was found in fetal calf serum, rat , mouse and horse serum.