Which method enables transcriptome-wide expression profiling?
Transcriptome-wide expression profiling demands technology capable of unbiased, high-throughput measurement across all transcripts present in cell. RNA-seq achieves this by massive parallel sequencing of complementary DNA libraries, yielding digital counts proportional to RNA abundance, enabling detection of differential expression, splicing, and novel isoforms genome-wide. EMSA and footprinting analyze protein-DNA binding at single locus level. RT-PCR quantifies few genes but lacks global scope. Only RNA-seq provides simultaneous interrogation of thousands of genes without requiring prior probe design, revolutionizing functional genomics and systems biology approaches.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.