Pipetting, contamination....

[Jose de las Heras]

"Tom Anderson" <ucgatan from ucl.ac.uk> wrote in message 
news:mailman.5.1171950975.5139.methods from net.bio.net...
> On Fri, 16 Feb 2007, Gaelle ayyildiz wrote:
>
>> would u please tell me how i can pipette my regents without
>> contaminating them with the micropipette (i.e. Gilson pipette)?
>
> Filter tips are an easy and effective way to avoid contamination, but
> normal good pipetting practice shouldn't result in a great deal of
> contamination. Obviously, you should avoid the muzzle of the pipette
> coming into contact with the liquid in the tip, by not pipetting volumes
> too close to the capacity of the tip. You should also avoid forming
> aerosols, by pipetting gently: draw the liquid up slowly (not glacially,
> but no so fast it jumps about, particularly with P1000s), and bring it
> smoothly to a stop at the top, rather than running straight into the stop.
> Other than that, i'm not sure - you could drop Gilson an email and ask
> them for some tips (as in advice, not plastic things!).
>
> tom
>
> -- 
> Tom Anderson, MRC Laboratory for Molecular Cell Biology, UCL, London WC1E 
> 6BT
> (t) +44 (20) 76797264   (f) +44 (20) 76797805   (e) 
> thomas.anderson from ucl.ac.uk


Good advice, Tom.
However, spending many hours working in the radiation room illustrates how 
easy it is to get your pipettes contaminated. No matter how careful you are, 
aerosols are formed at some point. That's why we ended up using filter tips 
as standard for any radioactive work. When your solution is not radioactive 
it's just not so easy to detect, but even the most careful researcher's 
pipettes get contaminated if they don't use filter tips.

Jose