Gene Expressio

In cancer studies, the changes of gene expression is what is concerning to scientists.  As a result, RNA is necessary to study changes in gene expression.  RNA is an extremly unstable molecule and it needs to be to ensure regulations of gene expression.  In order to study RNA effienctly, reverese transcription is used via reverse transcripase to create cDNA from the RNA template.  When the RNA is being studied, the introns have already been spliced out allowing for a precise understanding of the exact DNA sequence causing the regulation without introns interferring with it.  PCR can then be used to replicate the cDNA and allow for several copies of DNA to be used.  In PCR, there a phase where the reaction platues.  Therefore, there needs to be flourences and a window to see the levels of all the DNA to determine which sequences are amplyfying fastest.  Before the platue, the levels can be compared to see what gene is expressed most in the cancer cells.