Sequencing systems and methods

A method, comprising:

• a. contacting a growing strand hybridized to a template with a first reagent mixture comprising labeled, non-terminated nucleotides and reversibly terminated nucleotides of a first canonical base type and detecting a first signal indicative of incorporation of labeled, non-terminated nucleotides of the first reagent mixture in the growing strand, or lack thereof, to generate first sequencing data;
• b. reversing termination of a reversibly terminated nucleotide of the first reagent mixture incorporated in the growing strand;
• c. contacting the growing strand with a second reagent mixture comprising labeled, non-terminated nucleotides and reversibly terminated nucleotides of the first canonical base type and detecting a second signal indicative of incorporation of labeled, non-terminated nucleotides of the second reagent mixture in the growing strand, or lack thereof, to generate second sequencing data;
• and
• d. processing the first sequencing data and the second sequencing data to determine a length of a homopolymer sequence in the template.