Sparsely cross-linked "nanogels" for microchannel DNA sequencing

We have developed sparsely cross‐linked “nanogels”, sub‐colloidal polymer structures composed of covalently linked, linear polyacrylamide chains, as novel DNA sequencing matrices for capillary electrophoresis. The presence of covalent cross‐links affords nanogel matrices with enhanced network stability relative to standard, linear polyacrylamide (LPA), improving the separation of large DNA fragments. Nanogels were synthesized via inverse emulsion (water‐in‐oil) copolymerization of acrylamide and N,N‐methylenebisacrylamide (Bis). In order to retain the fluidity necessary in a replaceable polymer matrix for capillary array electrophoresis (CAE), a low percentage of the Bis cross‐linker (