Frequently Asked Questions - Pipettes
How does a pipette work?
IKA PETTE range piston lift pipettes meter in accordance with the so-called air cushion principle. An air cushion separates the sample in the tip of the pipette from the piston. Pressing the pipetting button causes the piston to slide downwards, pushing out some of the air. The resulting vacuum takes up liquid in the tip of the pipette when the button is released. Pushing the button again causes the piston to slide downwards again, pushing out the air, to deposit the liquid.
What measuring range do the pipettes cover?
The normal measuring range of pipettes extends from 0.1 ul to 10 ml. IKA covers the entire measurement range with 18 different fixed volume pipettes or with variable or adjustable pipettes.
What is the difference between backwards pipetting and forwards pipetting?
Forwards pipetting is often used for aqueous solutions, such as buffer solutions or diluted solutions.
Proceed as follows:
Push the pipetting button up to the first press point. Release the button slowly to take up the liquid. The liquid is deposited again by pressing to the second press point.
Backwards pipetting, or reverse pipetting, is more suited to liquids having high vapor pressures, high viscosity and a tendency to foam. In addition, the process is ideal for the pipetting of low volumes.
Proceed as follows: Push the pipetting button up to the second press point. Release the button slowly to take up the liquid. Then push the button up to the first press point to deposit the liquid. Liquid will remain in the tip.
What do we need to bear in mind when pipetting?
We recommend the following to get correct and precise pipetting results:
- Use matching pipette tips to achieve optimum results
- In order to prevent cross-contamination, use the pipette tips just once, or change it if different liquids are pipetted. Do not touch the opening in the tip of the pipette.
- Before the pipetting process, you need to make sure that the pipette, the tip of the pipette and the liquid to be pipetted are at the ambient temperature. It is also beneficial to wet the tip of the pipette with the liquid to be pipetted several times. I.e. taking up and dispensing the maximum volume.
- In order to prevent volume deviations, you must ensure that the pipette is held in as vertical position as possible when taking up the medium. In addition, the tip of the pipette should be immersed in the liquid by max. 2-5 mm during aspiration.
- After using the pipette, we recommend setting it to maximum volume and placing it in a pipette mounting unit, such as the LINEA.
- In order to ensure long-term pipetting accuracy, you should clean, calibrate and, if necessary, grease the pipette at regular intervals.
Further pipetting recommendations can be taken from the operating instructions.
How can I adapt the pipette to my requirements?
3 exchangeable handles, in various sizes and materials, are included in the scope of delivery. The choice of the right handle for your particular hand means that the pipette can be adapted to suit your individual requirements. This ergonomic optimization permits comfortable and wrist-friendly working, and ensures that the pipette sits in your hand perfectly in daily use easily to assess the working points. Precise and repeatable results are thus guaranteed.
What are the piston and the tip cone made from?
The piston and tip cone on the gray and yellow pipettes are made from DLC-coated stainless steel. DLC stands for diamond like carbon and is a diamond-like type of carbon which exhibits high levels of wear and corrosion resistance, together with particular hardness and low frictional indices. The piston and the tip cone of the blue, green and red pipettes are made from PPSU (piston) and PPS (cone). Both these materials are high-performance plastics which are characterized by high levels of chemical resistance and stiffness.
How can I prevent corrosion in pipettes? We recommend that you purchase only corrosion-resistant pipettes. The piston and tip cone on the IKA PETTE have a corrosion-resistant DLC coating and are made from chemically-resistant high-quality plastics. Corrosion inside the pipette can be prevented by always keeping the pipette upright. This means that liquids cannot enter the body of the pipette.
What benefits does the multifunction button have?
The multifunction button permits single-handed volume adjustment. In addition, the tip of the pipette can be ejected in any hand position, whilst the volume adjustment is securely locked whilst doing so. The round construction means that it can be operated easily by both left-handers and right-handers.
How do we clean and sterilize the pipettes?
We recommend always wearing protective gloves when cleaning the pipettes. Dismantle the lower section of the pipette and clean the parts with water containing a surfactant (a soap solution) or isopropanol (70%). Installations for removal are provided in the operating instructions that are available from the download area of the specific pipette. You should then flush the parts with distilled water and allow them to dry. If you prefer heat and high-pressure sterilization by autoclaving instead of chemical sterilization, then remove the filter from the IKA PETTE vario 0.5 - 5 ml / 1 -10 ml before autoclaving and replace it after autoclaving. All parts of the pipette are fully autoclavable at: 121 °C; 20 min; 1 bar over-pressure.
Do tips from other manufacturers fit IKA pipettes?
All the PETTE fix and vario models are compatible with pipette tips from most manufacturers. Pipette tips having the common color codes gray, yellow, and blue always fit on our pipettes, marked accordingly. A few special pipettes and tips are the exception.
How do you dismantle the pipette?
The IKA PETTE range of pipettes can be assembled and dismantled in just a few simple steps. The procedure is described in detail in the operating instructions. These are available in the download area for the specific pipette
Why don’t the pipettes have a CE-IVD mark?
The IKA PETTE range of pipettes are not laboratory equipment, but rather products for general laboratory requirements. For this reason, it is not permitted to attach a CE conformity mark to the pipette.
It is a fundamental fact that CE conformity can only be confirmed and a CE mark be attached to the product if there is an applicable EU Directive or EU Regulation for the product.
For example, the IVDD (In-Vitro Diagnostics Directive) applies to the In-Vitro Diagnostic Medical Products. This came into force on 25 May 2017 and becomes valid on 26 May 2022.
However, products such as reaction glassware, vessels, piston pipettes and lift pipettes are classified as general laboratory requisites (for general applications). There is currently no EU Directive or EU Regulation for this.
Note: Directive 98/79/CE of the European Parliament and Council dated 27 October 1998 concerning in-vitro diagnostics; the full text of the of the document is available on-line at http://europa.eu.int/eur-lex/pri/de/oj/dat/1998/l_331/l_33119981207de00010037.pdf. Medical Product Regulation dated 17 October 2001 (MepV, SR 812.213); the full text of the document is available on-line at www.admin.ch/ch/d/sr/8/812.213.de.pdf.
Why is it necessary to calibrate pipettes at regular intervals?
The precision of a pipette is of significant importance for the quality of the result. A regular calibration therefore ensures long-term accuracy and repeatability of the pipette.
How often do we need to calibrate pipettes?
The number of calibrations depends on several factors. This includes the frequency of use, the properties of the liquids to be pipetted and the maximum deviation set by the user. According to the most-used test standard DIN EN ISO 8655 for pipettes and their calibration, at least one calibration should be carried out per year.
How does IKA guarantee the precision of the pipettes?
All pipettes are calibrated in the factory at IKA, reliably and using the most modern robotics, in accordance with the test standard DIN EN ISO 8655.
Can you also calibrate the pipettes yourself? Yes, the IKA pipette calibration software (IPCS) is particularly user-friendly for calibration tests for the PETTE fix and vario.
Are tools required for resetting?
No, the PETTE fix and vario are designed in such a way that tools are not required for resetting.
How do you calibrate the pipettes yourself?
Please read the test standard DIN EN ISO 8655 to become acquainted with all the requirements. The most important steps are summarized below:
1. Measure the temperature and humidity in the calibration laboratory and prepare deionized water and a precision scales.
2. For the calibration of pipettes with adjustable volumes, select three volumes per pipette: the least, the most and a medium volume. Now weight the deionized water and carry out 10 pipetting procedures per volume. With fixed volume pipettes, the volume of the deionized water corresponds to the measuring range. Here again, 10 procedures are carried out.
3. Try out the pipette calibration software for planning, execution and documentation of all calibration tests, free-of-charge for 30 days. The quality of calibration improves with automatic transfer of the measured data from the scales, for example.
4. If the calibration was unsuccessful, please read the operating instructions to readjust the pipette and repeat the above steps.
Does IKA offer a calibration service for pipettes?
We would be pleased to carry out standardized calibration of your pipettes and we offer various different calibration packages. Our service team is available at all times to answer your questions.