A method for determining an efficiency of target enrichment from a DNA library, includes: adding a negative control sequence and a positive control sequence to the DNA library, or picking a negative control sequence and/or a positive control sequence from the library; determining a pre-capture amount of the negative control sequence and a pre-capture amount of the positive control sequence; performing enrichment of a target sequence from the DNA library using a bait sequence to produce a post-capture library; determining a post-capture amount of the negative control sequence and a post-capture amount of the positive control sequence in the post-capture library; and determining the efficiency of the target enrichment, based on the post-capture amount of the positive control sequence, the post-capture amount of the negative control sequence, the pre-capture amount of the positive control sequence, and the pre-capture amount of the negative control sequence.