Studies on cryopreservation of third-stage larvae of Parastrongylus cantonensis.
Attempts have been made to increase the survival rate of third-stage larvae of Parastrongylus cantonensis during cryopreservation. Parasites were obtained from experimentally infected snails, Biomphalaria glabrata. The maximum non-toxic concentrations of cryoprotectants dimethyl sulphoxide (DMSO) and glycerol were determined as 10% v/v in NCTC 109 medium. Different pre-cooling times and serum additives were assayed to determine their effects on the viability of larvae. Larvae pre-cooled at -20 degrees C for 15-20 minutes before transfer to -70 degrees C had the optimum survival rate. The presence of serum was essential for further cooling to -196 degrees C. There were no differences between native and heat-inactivated sera on the larval viability. The survival of larvae recovered after storage at -196 degrees C was higher in sera collected from the rat, man, or fetal calf than in sera collected from the mouse, dog, or horse. Viability assessed by mouse-infections showed that thawed larvae retained infectivity for susceptible hosts, but it was significantly lower than that of unfrozen control worms.
Chao
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D
Department of Biology, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic of China.
Wang
L C
LC
Chen
E R
ER
D017185:Angiostrongylus cantonensis / Q000187:drug effects / Q000254:growth & development*; D000818:Animals; D001700:Biomphalaria / Q000469:parasitology; D001769:Blood / Q000378:metabolism; D015925:Cryopreservation; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005260:Female; D005990:Glycerol / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000254:growth & development*; D051379:Mice; D008813:Mice, Inbred ICR
D005990:Glycerol; D004121:Dimethyl Sulfoxide