Patent ID: 8883999

Claim:
A method of incorporating labeled nucleotides into nucleic acid, comprising: a) providing i) a reaction chamber comprising a plurality of nucleic acid template molecules bound to a solid support, ii) a first solution comprising polymerase and a plurality of nucleotide analogues wherein each nucleotide analogue is labeled with a unique label and contains a removable chemical moiety capping the 3′-OH group, iii) a second solution comprising a cleaving agent, iv) a cleaving agent scavenger, wherein said cleaving agent scavenger is cystamine, and v) a wash solution; b) introducing said first solution into said reaction chamber under conditions wherein a first nucleotide analogue is incorporated by said polymerase; c) detecting the label of the incorporated nucleotide analogue; d) introducing said second solution into said reaction chamber under conditions such that the chemical moiety of the incorporated nucleotide analogue capping the 3′-OH group is removed by said cleaving agent leaving a 3′ hydroxyl group to enable the next nucleotide incorporation; e) washing said reaction chamber with said wash solution under conditions where some leftover cleaving agent remains in said reaction chamber; and f) introducing said cleaving agent scavenger into said reaction chamber under conditions where cystamine reacts with said leftover cleaving agent.