Giant Cells of Escherichia coli

Abstract
A mutant strain E. coli K-12 produced amorphous cells when grown in a variety of media. The lon- allele, known to increase the radiation sensitivity of the cytokinesis mechanism, was introduced into the mutant by means of conjugation. Cells of this re-combinant strain grew, after exposure to radiation, into giant amorphous cells, approximately 500 to 1,000 times the volume of a normal E. coli cell. These giant cells are analogous to the filaments formed after the irradiation of lon- fod shaped cells.