The specificity and sensitivity of an indirect and two (an 'ordinary' and a 'rapid') double sandwich
enzyme-linked
immunosorbent assay (ELISA) procedures for the quantitation of Calloselasma rhodostoma (Malayan pit viper)
venom were examined. The three assays were equally sensitive and the accuracy of the assays was not substantially affected by individual variation in the
venom composition. The specificity of the assays was examined against 26
venoms from snakes of the families Viperidae and Elapidae. While the double sandwich ELISA procedures were sufficiently specific to be used in the clinical immunodiagnosis of C. rhodostoma
bite in Malaysia, the indirect ELISA procedure exhibited extensive cross-reactivity with other Malaysian
pit viper venoms. Attempts were made to improve the specificity of the indirect ELISA procedure for the quantitation of C. rhodostoma
venom. A 'low ELISA cross-reactivity'
venom fraction (termed VF52) was isolated from C. rhodostoma
venom by repeated
Sephadex G-100 gel filtration chromatography. The indirect ELISA procedure using
antibodies to VF52 as immunoreagent showed an improvement in specificity. The use of the indirect ELISA procedure for the detection of C. rhodostoma
antibodies was also examined and the results show that the assay was sufficiently specific to be used for retrospective diagnosis of C. rhodostoma
bite in Malaysia, in particular when VF52 was used as the coating
antigen.