title: The use of membrane screen filters in the isolation of Plasmodium berghei sporozoites from mosquitos.
abstract: An improved procedure is presented for the isolation of Plasmodium berghei sporozoites from host mosquitos. The method employs filtration through a series of Nuclepore membranes followed by two consecutive centrifugations of the filtrate layered over Renografin-60 solutions of different densities. A Coulter Counter was used to compare isolations prepared by this technique with those prepared by a routinely employed discontinuous gradient method. When the sporozoite concentration in each preparation was standardized at 300 sporozoites per ml, isolations prepared by the new technique were significantly cleaner than isolations prepared by the discontinuous gradient method, containing an average of 1706 total particles per ml compared with 46 107 total particles per ml. The latter procedure was more effective, however, in removing viable microorganisms. Sporozoites isolated by both techniques were similar in immunogenicity and virulence.
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D016782:Apicomplexa / Q000302:isolation & purification*; D005374:Filtration / Q000295:instrumentation; D007158:Immunologic Techniques; D010962:Plasmodium berghei / Q000302:isolation & purification*