Griffith's experiment

Griffith described the phenomenon of transformation in two strains of pneumococci.

The first strain

  • Griffith experiment
    virulent;
  • infectious;
  • highly pathogenic;
  • kills its hosts (mice);
  • encapsulated with polysaccharide capsules;
  • they form colonies with smooth edges on the agar.

The second strain

  • mutant;
  • harmless;
  • they do not have polysaccharide capsules;
  • on agar soil they form colonies with wrinkled, rough edges.

The result of the experiment

Griffith killed and disrupted virulent pneumococci and mixed them with live non-virulent pneumococci. After further cultivation, he put these bacteria into the body of mice. The mice became ill later than if they received the same dose of lethal pneumococcus, but the end effect was lethal.

Continuity

Griffith's experiment was directly followed by a group around Oswald T. Avery in 1944.


References

References

AVERY, O T, C M MACLEOD a M MCCARTY. STUDIES ON THE CHEMICAL NATURE OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES : INDUCTION OF TRANSFORMATION BY A DESOXYRIBONUCLEIC ACID FRACTION ISOLATED FROM PNEUMOCOCCUS TYPE III. J Exp Med [online]. 1944, vol. 79, no. 2, s. 137-58, dostupné také z <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2135445/?tool=pubmed>. ISSN 0022-1007

Sources

  • OTOVÁ, Berta. Lékařská biologie a genetika. 1. vydání. Praha : Karolinum, 2008. 123 s. ISBN 978-80-246-1594-3.