[4] Singh also worked in the areas of molecular basis of sex determination, wildlife conservation forensics and evolution and migration of humans.

[5] Singh founded various institutes and laboratories in India, including the Centre for DNA Fingerprinting and Diagnostics in 1995, Laboratory for the Conservation of Endangered Species (LaCONES) in 1998, and Genome Foundation in 2004, aiming to diagnose and treat genetic disorders affecting the Indian population, in particular the under-privileged people residing in rural India.

Lalji Singh was born and raised in a small village Kalwari in Jaunpur District of Uttar Pradesh, India.

After completing his 12th standard in the science group at school, he attended Banaras Hindu University to pursue his graduation in Zoology and cytogenetics.

Singh scored the highest marks in his Master's degree class at BHU in 1966, and won the Banaras Hindu Gold Medal for standing first in order of merit.

[7] In 1971–72, Singh worked as a research associate at the Department of Zoology, University of Calcutta, and in April 1974, he was appointed as pool officer of CSIR.

[10] In June 1987, Singh returned to India and joined the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad, as a senior scientist.

These included being a member of the Governing Board of Indian Council of Agricultural Research (ICAR), New Delhi; chairman of the Research Advisory Council (RAC) of National Bureau of Animal Genetic Resources (NBAGR), Karnal; chairman of the RAC of Project Directorate on Poultry (PDP), Hyderabad; member of the advisory committee of Pharmacopeia Commission of India; chairman of the RAC of National Bureau of Fish Genetic Resources (NBFGR), Lucknow; member of the Board of Management of Sri Ramachandra University, Chennai and member of the Board of Governors of Indian Institutes of Science Education and Research (IISER) Mohali.

[10] Singh also served as director of the Genome Foundation, a non-profit organization aiming to develop cheap molecular diagnostics for genetic disorders prevalent in rural India.

[42][43][44] The first DNA-based test for establishing the species identity of an unknown biological sample pertaining to a case of wildlife crime, was conducted in that laboratory in 2000.

[45] Since then, the laboratory has undertaken thousands of such cases on a routine basis for the entire country and has revitalized the field of wildlife forensics.

[51][52] In 1982, Singh and his colleagues discovered that a tiny portion of the short arm of sex-determining Y chromosome was necessary and sufficient to convert a female mouse to male.

The fundamental research carried out by Singh and his colleagues in that area, led to conceptualization and establishment of the first DNA based diagnostic laboratory in the country.

[56] The fundamental DNA-based research carried out by Singh and his colleagues on primitive tribes including the tribal population of the Andaman and Nicobar Islands, provided critical insights into the evolution and migration of humans, suggesting the out of Africa route of modern humans about 60,000 years ago to the Andaman Islands.