A method of distinguishing nucleotide sequences for different nucleic acid molecules including the steps of (a) mixing a plurality of different nucleic acid molecules with polymerase molecules and nucleotide molecules, wherein the different nucleic acid molecules are attached to a surface in the form of an array of nucleic acid features; (b) determining a transient state of the polymerase molecules at the nucleic acid features; and (c) identifying a subset of nucleic acid features that correctly incorporate the nucleotide molecules based on the transient state of the polymerase molecules at the nucleic acid features, thereby distinguishing the nucleotide sequences for the different nucleic acid molecules.