Why is too much enzyme volume avoided in restriction digestion?

Correct answer: Storage glycerol can become high and increase star activity

The direct answer is option A: too much enzyme volume can add too much glycerol from the enzyme’s storage buffer and may increase star activity. Restriction enzymes are usually stored in a glycerol-containing solution so they remain stable. If a very large volume is added to the reaction, the final glycerol concentration can become too high. Under unsuitable conditions, the enzyme may cut DNA at sites similar to, but not exactly the same as, its normal recognition site. This relaxed, unwanted cutting is called star activity and reduces specificity. Option A is correct. Option B is wrong because more enzyme does not always improve DNA; excessive enzyme or unsuitable conditions may damage the intended pattern. Option C is meaningless because the enzyme is already a protein; it does not need to “become” one. Option D is too absolute: too much enzyme does not always cause no bands, although it can produce unexpected digestion patterns. The memory cue is: respect the recommended enzyme-to-reaction volume and glycerol limit.