Which one of the following approaches is generally not used for identifying an SNP?
Which one of the following approaches is generally not used for identifying an SNP?
Select an option to attempt
Correct Answer: Option A
Explanation
SNP identification methods: (1) Whole genome sequencing (WGS) — directly identifies SNPs at base-pair resolution. (2) RNA-Seq (transcriptome sequencing) — identifies SNPs in expressed regions (exonic SNPs/eQTLs). (3) DNA microarrays (SNP chips, e.g. Illumina BeadChip, Affymetrix) — hybridisation-based genotyping of hundreds of thousands of SNPs simultaneously. (4) Molecular beacons — stem-loop oligonucleotide probes with a fluorophore and quencher; hybridise to target and discriminate single nucleotide mismatches by fluorescence. (5) TaqMan genotyping, pyrosequencing, KASP assay — SNP genotyping methods. PROTEIN SEQUENCING (Edman degradation or MS/MS): sequences the amino acid chain — can detect amino acid polymorphisms but CANNOT directly identify the underlying nucleotide change (same amino acid can be encoded by different SNP-containing codons; synonymous SNPs are completely invisible to protein sequencing). Therefore protein sequencing is NOT generally used for SNP identification.