I am recapping for the exam in transcriptomics and stumbled into a question about microarray. So, our regular workflow is to
- extract RNA from cells
- generate cDNA from the initial RNA using reverse transcription
- transcribe cRNA from cDNA
- label cRNA with biotin
- fragment biotin labeled cRNA
- hybridize to a plate, scan and quantitate
So the question is - since we use RNA for the further quntification steps why should we perform reverse transcription+transcription to produce cRNA while we could just use the initial RNA?
Is the cRNA more stable than RNA? Or we already make labeled cRNA using labeled nucleotides?