Practice question

5 prime RACE technique aims to clone unknown sequence upstream of known internal messenger RNA region, particularly transcription start site and 5 prime untranslated region. Total RNA is reverse transcribed using gene-specific antisense primer to produce first-strand complementary DNA. Subsequent addition of homopolymeric tail at 3 prime end of complementary DNA by terminal deoxynucleotidyl transferase provides universal priming site. This tailed complementary DNA subsequently serves as template for PCR amplification using nested gene-specific primer and oligo-dT-anchor primer. Hence methodology fundamentally combines reverse transcription with polymerase chain reaction and enzymatic tailing.