High‐Performance Sieving Electrophoresis for Single‐Nucleotide Polymorphisms with a Structuring Hydrogel Network

Although DNAs with single-nucleotide difference (e.g., 1000 and 1001 nt) can be resolved by capillary electrophoresis (CE), separation of the same length DNA with single-nucleotide difference is still a great challenge, which is caused by the structural or thermodynamical fluctuation of the sieving matrix. Here, a homogeneous tetra-arm poly (ethylene glycol) (Tetra-PEG) polymer network is synthesized in a capillary, and single monoprotic ssDNA is successfully separated in the capillary filled with cross-linked Tetra-PEG polymer. Results show that the separation performance in both slab-gel electrophoresis and CE is dramatically improved by Tetra-PEG gel than polyacrylamide gel as sieving matrix. Moreover, separation based on Tetra-PEG gel depends on not only the DNA size but also the chemical modification and DNA sequence, indicating that it is an ideal alternative to polyacrylamide gel.