What evidence suggests you have the correct recombinant plasmid in the gel image?

What evidence suggests you have the correct recombinant plasmid in the gel image?

• A. The R+ lane shows two fragments of the expected sizes.
• B. The R- lane is completely linear.
• C. The ladder shows no bands.
• D. The loading dye moves toward the negative electrode.

Answer: (A)

Verifying a recombinant plasmid by restriction digest and gel looks for a specific pattern: after digestion, the insert and the vector should separate into two fragments whose sizes match what you predicted from the map. If the R+ lane shows two bands at the expected sizes, that matches the designed plan for the recombinant plasmid, indicating the insert is present and in the correct configuration. The other ideas don’t provide that definitive confirmation: a completely linear R- lane could result from digesting a non-recombinant plasmid or from incomplete digestion, which doesn’t prove the insert’s presence; a ladder with no bands signals a gel or loading problem rather than anything about the plasmid; and the loading dye’s movement is just a generic feature of electrophoresis, not evidence of the clone’s identity.

Verifying a recombinant plasmid by restriction digest and gel looks for a specific pattern: after digestion, the insert and the vector should separate into two fragments whose sizes match what you predicted from the map. If the R+ lane shows two bands at the expected sizes, that matches the designed plan for the recombinant plasmid, indicating the insert is present and in the correct configuration. The other ideas don’t provide that definitive confirmation: a completely linear R- lane could result from digesting a non-recombinant plasmid or from incomplete digestion, which doesn’t prove the insert’s presence; a ladder with no bands signals a gel or loading problem rather than anything about the plasmid; and the loading dye’s movement is just a generic feature of electrophoresis, not evidence of the clone’s identity.