Purity: > 85% by SDS - PAGE Format: Liquid. 20mM Tris-HCl buffer (pH8.0) containing 40% glycerol, 0.15M NaCl, 1mM DTT . DARS, also known as aspartyl-tRNA synthetase, catalyzes the specific attachment of an amino acid to its cognate tRNA in a 2 step reaction: the amino acid (AA) is first activated by ATP to form AA-AMP and then transferred to the acceptor end of the tRNA. Recombinant human DARS protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.