Practice question

Early SNP genotyping relied on radioactive allele-specific oligonucleotide hybridization and autoradiography with safety concerns and limited throughput. Modern SNP chip or microarray technology immobilizes thousands to millions of synthetic oligonucleotide probes on solid surface, labeling target DNA with fluorescent dyes, enabling massively parallel genotyping without radioisotopes. Differential hybridization signal intensity distinguishes homozygous and heterozygous genotypes automatically. RFLP traditionally required radiolabeled probes, RAPD and VNTR need electrophoresis. Microarray platforms provide automated, safe, high-throughput non-radioactive typing essential for genome-wide association studies and personalized medicine.