Inefficient Cleavage Due to Single Recognition Site

Symptom

Incomplete digestion persists despite adequate enzyme units and incubation time; some restriction enzymes require two recognition sites on the same DNA molecule for efficient cleavage.

1. 1 Enzyme requires presence of two recognition sites for efficient catalytic activity
2. 2 DNA substrate contains only single recognition site

1. 1 Check enzyme product information to confirm two-site requirement
2. 2 Use alternative restriction enzyme with same specificity but no two-site requirement
3. 3 Add control DNA fragment containing the recognition site to provide second site in trans
4. 4 Increase enzyme concentration and incubation time for partial activity on single sites

Related Video (3)

New England Biolabs ★ 85

Cloning With Restriction Enzymes

"Directly covers guidelines for choosing restriction enzymes and performing cloning digests, the exact technique where single-site inefficiency occurs."

Addgene ★ 80

Restriction Digest Analysis

"Demonstrates a real restriction digest with gel analysis, letting viewers observe incomplete digestion phenotypes and interpret banding results."

New England Biolabs ★ 70

Episode #56: Molecular Cloning Series: Restriction Enzymes 101

"Explains restriction enzyme fundamentals including how enzyme behavior varies, providing context for why some enzymes need two sites for efficient cleavage."