Esther Miriam Zimmer Lederberg

American microbiologist; 1952 she & husband Joshua performed an experiment that helped show many mutations are random, not directed; known for the discovery of a bacterial virus, the bacterial fertility factor F; devised the 1st implementation of replica plating & furthered the understanding of the transfer of genes between bacteria by specialized transduction; maintained, named & distributed plasmids of many types microbiologist & pioneer of bacterial genetics; 1951 discovered lambda phage, a virus that infests E. coli bacteria, that was used to study genetics recombination & gene regulation.