Mary performs a PCR reaction and runs it on an agarose gel, using 100-bp ladder
ID: 186916 • Letter: M
Question
Mary performs a PCR reaction and runs it on an agarose gel, using 100-bp ladder as her molecular weight standard. She images the gel using UV light and sees NO bands (no band in her PCR reaction and no bands for her ladder). Which of the following could explain these results? Explain each answer.
1. Mary forgot to add Gel Red when pouring the gel.
2. Mary's PCR product had an unusually high % of G and C bases.
3. Mary connected the electrodes to her gel incorrectly, swapping the positive and negative poles.
Explanation / Answer
the answer is that the pcr product had an unusually high % of g and c bases.
If the template concentration is too high,the polymerase can be inhibited due to carryover of inhibitors or inefficient denaturation.Reduce the number of cycles,reduce the concentration and increase in denaturation time shows the bands.