As one kind of chiral selector, calf thymus DNA (ct DNA) was used for the chiral separation Of L,D-tyrosine and L,D-tryptophan. After mixed with ct DNA and dialyzed in water, L,D-tyrosine or L,D-tryptophan exhibited an obvious concentration difference in permeate solution. Their D-enantiomers preferentially existed in the permeate solution while L-enantiomers preferentially existed in the feed solution. This indicates that ct DNA prefers binding to L-enantiomers rather than binding to D-enantiomers in feed solution, and the binding between them is enantioselective. Published by Elsevier B.V.