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Do I need sterile RT-PCR tubes? - Real time PCR (Sep/09/2008 )

I have been using DNase, RNase free tubes for RT-PCR but I have realised that they do not come sterile, should I be autoclaving them before I sue them or does this not matter?


-Patrick Coovans-

I do not think you need autoclave them unless you have trouble with them.


There was a very interesting topic on sterile tubes, just a month or two ago. I recommend it cordially.

(yes, it is important)


You do not need to autoclave PCR tubes, and it may be worse, not better to do so. Sterile is not the same as clean. You care about contaminating DNA (primed by your primers) not a few cells which won't replicate at 95C. An autoclave can be a source, not a cure for this contamination.


if this is a communal autoclave, than people will be autoclaving media, which can occasionally spill. This media (eg LB, EMM) will contain DNA and RNA. The same autoclave may also be used to sterile old moldy plate before disposal.

In my building, the autoclaves are loaded with 2/3 deionised water and 1/3 tap water. It appears the autoclave needs the ions to reduce corrosion. So, your autoclave maybe loaded with several liters of tap water, which will bring in DNA from the bacteria and dead bacteria in the water supply.

So I agree with phage434, if the plastic is DNA-RNA free, don't autoclave. The PCR run to ~95 Celsius should kill nearly all bugs if you are worried.


I have also had the same experience as above mentioned.

I also have experienced tube that did not close as tightly after being autoclaved and thus resulting in some or most of my sample evaporating during PCR.

I must admit I probably had very cheap tubes.