 From 1967 to 1975 he worked as a Lecturer, Reader and Professor of Physiology at NRS Medical College, Kolkata.He created history when working with Sunit Mukherji, a Cryobiologist and Gynecologist Dr. Saroj Kanti Bhattacharya.He became the first physician in India (and second in the world after British physicians Patrick Steptoe and Robert Edwards) to perform the in vitro fertilisation resulting in a test tube baby "Durga" (alias Kanupriya Agarwal) on 3 October 1978.