[In vitro analysis of cross immunoreaction between CGRP and endotoxin in CGRP radioimmunoassay]

In the present study, the effect of endotoxin on the radioimmunoassay of calcitonin gene-related peptide (CGRP) was investigated by method of radioimmunoassay. The results showed a competitive combination of endotoxin at high-concentrations (higher than 5 micrograms/ml) with multiclonal antibody of CGRP, and the cross immunoreaction ratio between CGRP and endotoxin was 5.6 x 10(-6). The mixed endotoxin in samples was effectively cleared through C18 column purification. The data indicated that endotoxin interfered CGRP radioimmunoassay in vitro at high concentrations. The influence of endotoxin on CGRP radioimmunoassay can be avoided through C18 column purification for the endotoxin-containing samples.