Which technique is most likely to detect a new HLA-B allele with a point mutation in exon 3?

The technique that is most effective for detecting a new HLA-B allele with a point mutation in exon 3 is sequencing-based typing (SBT). SBT involves directly sequencing the DNA region of interest to identify specific mutations at the nucleotide level. This method is particularly valuable for detecting point mutations, which are small alterations in the DNA sequence, as it provides a highly sensitive way to differentiate between closely related alleles.

By sequencing the exon where the mutation is hypothesized to occur, one can accurately determine the exact nucleotide changes present. This precision is crucial when identifying new alleles, especially in the context of HLA typing, where a single nucleotide change can lead to significant differences in antigen presentation and immune response.

Other techniques, while useful in various contexts, may not provide the same level of detail. For instance, PCR-SSP relies on specific primers to amplify known alleles and may not effectively detect novel alleles created by mutations. PCR-SSOP is designed for hybridization with probes specific to known alleles, making it less suitable for identifying previously unknown mutations. RFLP can detect large changes or polymorphisms based on restriction enzyme digestion patterns but lacks the sensitivity for single nucleotide changes typical of point mutations. Thus, SBT