Figure 7.

High-temperature disintegration of oligonucleotide substrates. (A) Directed integration to a site with a mismatched base pair. (B) Three targets, differing in the sequence of 20 bp flanking one side of the mismatch (red lines), were labeled at the indicated 5′ end. After integration, complexes were separated from free target on agarose gels, subjected to in-gel disintegration at the indicated temperatures, and electrophoresed on denaturing polyacrylamide gels. ^*, unexpected product. (C) Substrate with T_m=65°C was labeled either as in (B) (lanes 1 and 2) or at the 3′ end of the bottom strand as shown (lanes 3 and 4). Reactions were at 55°C as described in (B), except that lanes 2 and 4 contained Ca²⁺. See text for details. (D) Graphical representation of reactions in (B). ‘% disintegration' refers to % of input substrate converted to the 76 nt product.