Dr Chatterjea elucidated the aetiopathogenetic aspects of the common disorders of the human red cells, unfolding the spectrum of hereditary disorders of human haemoglobin as prevailing in India. His discovery of haemoglobin-E in Bengalis and comprehensive studies on haemoglobin-E thalassaemia disease from clinical, haematological, biochemical, biophysical and genetical points of view have provided new information and greatly enriched the relevant areas of contemporary medical sciences.