Cryopreservation of Angiostrongylus cantonensis third-stage larvae

An optimum protocol for the cryopreservation of third-stage larvae (L3) of Angiostrongylus cantonensis was determined by: (i) use of different dimethyl sulphoxide (DMSO) concentrations; (ii) use of different FBS concentrations in RPMI-1640 medium; and (iii) variation in the thawing temperature. Studies showed that with concentrations of DMSO at 4.8% and FBS at 40% and a thawing temperature of 43 degrees C, L3 survival assessed by motility was highest at 56%. The infectivity of the cryopreserved L3 of A. cantonensis was 20% compared to controls obtained from slugs.