Expression of LdTPI in prokaryotic cells, whole cell lysate (WCL) of pET 28a+LdTPI transformed E. coli separated on 12% SDS-PAGE and stained with Coomassie brilliant blue, M: Molecular wt. markers; Lane 1: WCL before IPTG induction, lane 2: WCL after IPTG (1.0 mM) induction at 18°C (A); Purification of rLdTPI, M: Molecular wt. markers, Lane 1: wash fraction containing nonspecific proteins also and Lane 3 & 4: eluted purified protein (B); Western blot analysis using anti-LdTPI antibody raised in rabbit, M: Molecular wt. Markers, Lane 1: uninduced WCL of E. coli, Lane 2: induced WCL of E. coli, Lane 3&4: WCL and SLD of L. donovani, and Lane 5: purified rLdTPI (C); Western blot analysis of rLdTPI with patients’ serum. M: Molecular wt markers, Lane 1&2 blot with rLdTPI (D). Confirmation of LdTPI expression in HEK cell line by western blotting. M: Molecular wt. markers, Lane 1: WCL of non transfected cells, Lane 2: WCL of LdTPI-DNA construct transfected cells (E).