I saw three bands around base pairs of 1500, 1200, and 700 in the G-NTC for a column with DNA extracted from a human. Any ideas for the reasons of said contamination would really help.
Hi There,
I agree with Celine. Change your reagents (ie. get new dNTPs, waters, primers, etc) for your Master Mix. If it is clean next time, it means one of your reagents got contaminated in the previous round. Also, when pipetting your master mix into the negative tube, use a fresh, clean tip or dispense the master mix into that tube first before you add it to your DNA tubes. Sometimes it could be the result of simple pipetting error.
If you have access to a biosafety cabinet, you can also try setting up your PCR in the unit, after you've sterilised it (and all of your pipettes, ice box, racks, gloves, etc) under UV light for 10 mins (usually a feature on most biosafety cabinets). Otherwise, just clean your pipettes with 100% ethanol and RNase Away and wear gloves if you have. Filter tips may also help.
That usually works for me! Best of luck!
Jennifer
Hi Greg,
You may have a contamination, the best is to change your solution and do it again.
Celine
Hi There,
I agree with Celine. Change your reagents (ie. get new dNTPs, waters, primers, etc) for your Master Mix. If it is clean next time, it means one of your reagents got contaminated in the previous round. Also, when pipetting your master mix into the negative tube, use a fresh, clean tip or dispense the master mix into that tube first before you add it to your DNA tubes. Sometimes it could be the result of simple pipetting error.
If you have access to a biosafety cabinet, you can also try setting up your PCR in the unit, after you've sterilised it (and all of your pipettes, ice box, racks, gloves, etc) under UV light for 10 mins (usually a feature on most biosafety cabinets). Otherwise, just clean your pipettes with 100% ethanol and RNase Away and wear gloves if you have. Filter tips may also help.
That usually works for me! Best of luck!
Jennifer
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