Thymocyte nuclear protein 1, also known THYN1, is highly conserved among vertebrates and plant species and may be involved in the induction of apoptosis. Also, THYN1 in the thymocytes was mainly localized in the nucleus, as recently demonstrated in lymphoma cells, indicating that the THYN1 resides in the nucleus, irrespective of the cyclic or resting stage of the cell cycle. Recombinant human THYN1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.