Which of the following techniques can be used to detect abnormal gene expression levels?
Correct answer: B. Northern blot hybridization
Northern blot hybridization is a technique that detects the presence and quantity of specific RNA molecules, making it suitable for detecting abnormal gene expression levels. ASO (alkali-denatured DNA probes) can detect mutations but not gene expression levels directly. Southern blot hybridization is used to detect DNA sequences in genomic DNA, SSCP (single-strand conformation polymorphism) is used to identify point mutations, and RFLP (restriction fragment length polymorphism) is a genetic marker detection method.