__: quicker and more sensitive
o Analysis of hummingbird β-globin gene expression with this begins similarly to Northern blotting, with the isolation of mRNAs from different developmental stages of hummingbird embryos. Reverse transcriptase is added next to make cDNA, which then severs as a template for PCR amplification using primers from the β-globin gene. When the products are run on a gel, copies of the amplified region will be observed as bands only in samples that originally contained the β-globin mRNA.
o In the cause of hummingbird β- globin, we might expect to see a band appear at the stage when RBCs begin forming, with all subsequent stages showing the same band. RT-PCR can also be carried out with mRNAs collected from different tissues at one time carried out with mRNAs collected from different tissues at one time to discover which tissue is producing a specific mRNA.
Reverse transcriptase- polymerase chain reaction, or RT-PCR