We were running PCR for a 450bp bacterial V1 and V2 region product with each 30ng of either cDNA or DNA. But the bands in the gel appeared stronger for the cDNA (as in RNA) and the DNA was very less intense (around only half the intensity of the RNA). Is there an explanation for this? it should be the same intensity because we use the same amount of nucleic acid?
If you are comparing cDNA with gDNA (I presume this is what you mean??) then you would expect a stronger signal, weight for weight, from cDNA. cDNA will be enriched in the transcribed/expressed sequences where as gDNA will contain these AND all the non coding sequences, therefore weight for weight the cDNA will contain more copies of the sequnce of interest.
I accepting Marcus statement. Copy number of bacterial V1 and V2 region in 30ug of cDNA will be much higher than gDNA. PCR is just a xerox machine which will multiple particular gene - no of copies in preferable condition.
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Biology
- Biomolecules
- Nucleic Acids
- DNA