On the combined action of drugs on the lambda prophage induction in Escherichia coli K12 cells.

: The capability of methotrexate, jododeoxyuridine and 5-fluorouracil to induce lambda prophage was compared when given alone or in combination. All these drugs were found to cause inducing conditions in Escherichia coli K12(lambda) cells. Combined action of jododeoxyuridine and methotrexate resulted in a pronounced increase in the number of free phages compared with that resulting the treatment either with methotrexate of jododeoxyuridine alone. Treatment with 5-fluorouracil caused inactivation of plaque forming ability in cells induced with methotrexate.