He completed a postdoctoral fellowship at Harvard Medical School, where he studied DNA replication.
After joining the faculty at Harvard Medical School and Dana–Farber Cancer Institute in 1978 and establishing his own laboratory, he focused his research on DNA recombination.
[2] Kolodner has made fundamental contributions to the understanding of the mechanisms of genetic recombination,[3] DNA mismatch repair[4] and the pathways that prevent genome instability.
In both cases, Kolodner reported his findings simultaneously with Bert Vogelstein at Johns Hopkins University.
[1] Kolodner also discovered that epigenetic silencing of MLH1 is the cause of much more common sporadic mismatch repair defective cancers.