Phasing correction

Abstract

Memory efficient methods determine corrected color values from image data acquired by a nucleic acid sequencer during a base calling cycle. Such methods may: (a) obtain an image of a substrate (e.g., a portion of a flow cell) including a plurality of sites where nucleic acid bases are read; (b) measure color values of the plurality of sites from the image of the substrate; (c) store the color values in a processor buffer of the sequencer's one or more processors; (d) retrieve partially phase-corrected color values of the plurality of sites, where the partially phase-corrected color values were stored in the sequencer's memory during an immediately preceding base calling cycle; (e) determine a prephasing correction; and (f) determine the corrected color values. In various implementations, these operations are all performed during a single base calling cycle. In certain embodiments, the methods additionally include using the corrected color values to make base calls for the plurality of sites. Sequencers may be designed or configured to implement such methods.