In the R- lane, what would indicate multiple plasmid configurations?

In the R- lane, what would indicate multiple plasmid configurations?

• A. A single clean band
• B. Two or three distinct bands
• C. No bands
• D. A smear across a range

Answer: (B)

Plasmids can adopt different shapes, or conformations, that migrate at different speeds on a gel. In the R-lane, seeing two or three distinct bands means more than one plasmid form is present (for example, supercoiled, relaxed circular, and possibly linear). Each form runs as its own band, so multiple bands indicate multiple configurations coexisting. A single clean band would suggest a uniform form, a smear implies degraded or highly heterogeneous fragments, and no bands mean no DNA was loaded.

Plasmids can adopt different shapes, or conformations, that migrate at different speeds on a gel. In the R-lane, seeing two or three distinct bands means more than one plasmid form is present (for example, supercoiled, relaxed circular, and possibly linear). Each form runs as its own band, so multiple bands indicate multiple configurations coexisting. A single clean band would suggest a uniform form, a smear implies degraded or highly heterogeneous fragments, and no bands mean no DNA was loaded.