Separation of Isospora (Toxoplasma) gondii cysts and cystozoites from mouse brain tissue by continuous density-gradient centrifugation

Parasitology. 1981 Aug;83(Pt 1):103-8. doi: 10.1017/s0031182000050071.


A simple, quick and reproducible method consisting of density-gradient centrifugation of homogenized infected mouse brain tissue on Percoll is described for the isolation and purification of cysts of Isospora (Toxoplasma) gondii. A 100% recovery of cysts, with 74.2% in a single fraction with a specific gravity of 1.056, was obtained by overlaying homogenates of infected mouse brains on a pre-formed Percoll gradient and centrifugation at low g forces. With this procedure recovery was independent of the age of the cysts. Titration of purified cystozoites showed there to be no loss of infectivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / parasitology*
  • Centrifugation, Density Gradient
  • Isospora / growth & development
  • Isospora / isolation & purification*
  • Mice
  • Parasitology / methods
  • Povidone
  • Silicon Dioxide


  • Percoll
  • Silicon Dioxide
  • Povidone