Lane 2 shows two bands, while Lanes 1 and 3 each show one. What does the Southern blot most likely indicate about Patient 2?
- Acheck_circle
Patient 2 is heterozygous for two restriction-fragment alleles at this locus.
- B
Patient 2 has no DNA in the lane.
- C
Patient 2's DNA was not digested.
- D
Patient 2 is homozygous and has a deletion.
Explanation
Southern blots detect specific DNA fragments by hybridization to a labeled probe. Two bands of different sizes in one lane suggest a heterozygote inheriting two distinct alleles distinguished by a restriction-site polymorphism.