Frequently Asked Questions

Frequently Asked Questions

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Due to the increased vapour pressure of methanol we recommend to pre-wet at least 3 times and perform reverse pipetting technique.

A 99 % solution of n-amyl alcohol is a highly viscous solution for which we recommend an instrument which works with positive displacement principle. These instruments have an integrated piston in the tip that ensures full volume delivery. 

For dispensing an organic solvent it is best to use a positive displacement device. Positive displacement principle devices are most suitable for precise and drip-free dispensing of liquids with high vapor pressure. Since the liquid is enclosed in a tip with integrated piston the solvent vapor does not get into direct contact with the instrument. 

Both dichloromethane and n-hexanol have a very high vapor pressure. Using a normal air-cushion pipette would lead to dripping of the liquid and inaccurate volume delivery. For that reason positive displacement instruments should be used.  

Following contamination of pipettes with radioactive liquids, we recommend putting the contaminated parts in a complex-forming liquid or special cleaning solution. After that, rinse very thoroughly with distilled water and let dry. Grease piston lightly afterwards.

An adjustment of air-cushion pipettes is required for solutions with a density > 1.2 mg/µL. Note that variable manual pipettes turn into "fixed-volume pipettes" when being adjusted. They can only be adjusted for one volume and not across the entire volume range. Sophisticated manual pipettes have a user adjustment for temporary adjustment purposes. This user adjustment can easily be set back to manufacturer settings without the need for recalibration. 

No, it is not necessary to regrease the piston of Eppendorf pipettes after autoclaving.

No. It can be autoclaved in one piece (121 °C, 1 bar, 20 min).

Vapor will penetrate the inside of the pipette during autoclaving but this will not cause damage. We tested our pipettes with 175 autoclaving cycles (121 °C, 1 bar, 20 min). The number of respective tests chosen corresponds to an average of 5 years of use.

We recommend to wet a cloth with water or 70 % isopropanol and wipe the pipette to remove contamination outside of the pipette. 

For decontamination of a pipette wipe off the outer surface with disinfectant, DNA/RNA decontamination agent or 70 % isopropanol. After the exposure time of the disinfectant, rinse thoroughly with demineralized water. This step is especially important if subsequent decontamination steps are performed such as UV-light or autoclaving. Some pipettes may be temporarily subjected to UV light under a sterile bench. We recommend  the use of a Hg-lamp, 254 nm, 30 W. The distance between lamp and pipette should be approx. 60 cm. Some pipettes are even fully autoclavable.

Consider that pipettes should be easy to clean. Only the lower part should be cleaned on a regular basis, in accordance with the frequency of use. The lower part of the single-channel and multi-channel pipettes should be easily removable for cleaning purposes.

The RFID chip is used to clearly identify an instrument. Identification data, e.g. serial number or results of quality control test of manufacturer, are stored on the RFID chip. These data can not be changed or deleted.

Tips with low retention properties will grant an advantage especially during pipetting of solutions containing detergents, such as PCR master mixes, enzyme solutions and many buffers. These tips are characterized by significantly improved flow performance, thus achieving more economic use of expensive reagents, while valuable sample material is used effectively. Furthermore, reproducibility is improved, since wetting of the tip is dependent on both user and handling (for example: pipetting speed) and can therefore vary considerably.

Yes. Foam formation is rarely observed with the use of low retention tips. This facilitates the handling of these solutions and increases reproducibility.

The self-sealing mechanism works best with aqueous solutions, most acids and bases. Strong acids and bases might not be blocked properly and increase the risk of damaging the pipette if accidental over-pipetting occurs. For very aggressive solutions we recommend positive displacement systems where the sample is secured in the tip without any contact to the liquid handling instrument.

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