Frederick Griffith’s experiment identifying a ″transformation factor″ responsible for heredity

Injection of living SIII bacteria kills mice. Heat-killed SIII do not kill mice, nor do living RII bacteria . Coinjection of a mixture of heat-killed SIII and living RII bacteria results in mouse death by SIII infectionInjection of living SIII bacteria kills mice. Heat-killed SIII do not kill mice, nor do living RII bacteria . Coinjection of a mixture of heat-killed SIII and living RII bacteria results in mouse death by SIII infection

9 0 Heat-killed type Slll 0 0 LIVIng type Slll Heat-killed type SIII LIVIng type RH and living type Rll “ © \ I I / l / l / \\ ’ C /‘ // :Li‘f‘ ,/ r“ // :‘CV\ // InjecF InjecF Inject,\ Inject,\ mouse mouse lives mouse lives mouse dies dies . i Q i ’ ,1 / ”‘V I S" J j X, l i l i I l l l I l I l l l I I ll l I Live type Slll bacteria recovered Live type SIII No bacteria bacteria recovered No bacteria recovered recovered Conclusion: Hereditary molecule transformed RII bacteria into SIII bacteria.