A composition is provided comprising a negatively charged group, an oligonucleotide sequence and at least none or one nuclease-resistant linkage group to form a chemically-enhanced primer. The chemically-enhanced primer can be used for sequencing and fragment analysis. Methods for synthesizing the primer as well as a method of preparing DNA for sequencing and a method of sequencing DNA and kits containing the chemically-enhanced primer are also provided. The method of sequencing DNA can comprise contacting amplification reaction products with the composition under conditions in which excess amplification primer is degraded by the nuclease and the chemically-enhanced primer is essentially non-degraded.