Autoclaving is a BAD way of getting rid of contaminations. DNA is heat stable.

First, you must identify where the contamination comes from. This is a very difficult task. Best is to exchange ALL chemicals and pipettes. Also to prepare the reactions in a different lab/house. If the reaction then is negative, one can step by step return to the old lab, pipettes, chemicals and check at what point the contaminations come back in. Be aware of the possibility that several places and reagents can be contaminated.

Good luck.

PS: some people say the only way to really get rid of contaminations is to burn down the whole lab...

Autoclaving is a BAD way of getting rid of contaminations. DNA is heat stable.

First, you must identify where the contamination comes from. This is a very difficult task. Best is to exchange ALL chemicals and pipettes. Also to prepare the reactions in a different lab/house. If the reaction then is negative, one can step by step return to the old lab, pipettes, chemicals and check at what point the contaminations come back in. Be aware of the possibility that several places and reagents can be contaminated.

Good luck.

PS: some people say the only way to really get rid of contaminations is to burn down the whole lab...

In our lab we routinely use a product called ''Roti Nucleic acid free'' from Carl Roth to clean our pipettes works well. You can also disassemble your pipette and place it under UV light for 1 hour, it will also get rid of any RNA contamination.

RNA contaminations are not such a big problem...

Using pipette tips with filters may help as well.

hi, in our lab, time to time we do fumigate the whole wet lab section. It really helps us.

You can use cleansing solutions (such as DNA OFF) that eliminate DNA contamination OR you can use UV exposition for 10 minutes.

You have to prepare your chemicals for PCR in a different room ("pre-PCR") that the one for DNA extraction and the one for post-PCR . You should use filter tips for the reagents necessary for your PCR reaction.