US Patent 10400272 Methods and compositions for stabilizing nucleic acid-nucleotide-polymerase complexes

Methods, compositions, kits and apparatuses that include a fluid, the fluid containing a ternary complex and Li+, wherein the ternary complex includes a primed template nucleic acid, a polymerase, and a nucleotide cognate for the next correct base for the primed template nucleic acid molecule. As an alternative or addition to Li+, the fluid can contain betaine or a metal ion that inhibits polymerase catalysis such as Ca2+. In addition to Li+, the fluid can contain polyethylenimine (PEI) with or without betaine.