Griffith's experiment

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

The first strain

 * Griffith experiment.svgent;
 * 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.

Related articles

 * Parasexual processes in bacteria
 * Conjugation
 * Transduction
 * Genetics in data