Pre-soaking Pipettes

Question:
Why is it important to pre-soak pipettes in 1% Alconox or Liquinox before washing in pipette siphon washer with Alcotabs?

Answer:
The most common problem in pipette cleaning is residues that dry on after use and prior to cleaning. This problem is attributed to the failure to pre-soak the pipettes immediately after use. Our technical experts at Alconox recommend placing soiled pipettes in 1% Alconox or Liquinox solution immediately. For the purpose of detergency, it does not matter if pipettes are place tips up or tips down during pre-soak. The important thing is to make sure the pipette is completely immersed in solution with no part exposed to air where there would be a meniscus to potentially leave a ring or even an etch the pipette. For fewer broken pipette tips, it is recommended to place pipettes tips upward, if possible. However, for cleaning extremely viscous or difficult residues there is possibly a theoretical advantage to putting the pipettes in tips down to pre-soak because when they are lifted out of the pre-soak any loosely adhered residue or particulate will drain out the bottom and not have to pass thru the entire length of the pipette before it is removed.