Lack of accuracy in pipetting ruining your day at the laboratory? Inaccurate pipetting can often result in inaccurate stock solutions and unreproducible experiments. But worry not! We have some simple yet very crucial tips that can help perfect your pipetting technique. Here are 8 tips to help you improve:
1.Pre-wet the pipette tip
The next time you use a pipette, observe the tip precisely. When the liquid is dispensed from the pipette, a coating of the liquid is left on its tip. This slightly reduces the actual volume dispensed than what is initially read. An easy solution to handle the liquid in this process correctly is to pre-wet the tip before you start the process to better the accuracy of readings. Draw up the liquid into your pipette and then dispense back into the original vessel. The coating on the tip will now transfer into the receiving vessel when you draw up the liquid again, leaving no traces behind- this method is called pre-wetting the tip.
2.Note the ambient temperature:
Often individuals working in a science laboratory face inaccuracy problems due to unrecognizable reasons. One of the most common reasons can be the difference in the ambient temperature. The person or company that calibrated the pipette might have done so at room temperature. On the other hand, if you are working in a cold room, the pipette used will not dispense the displayed volumes.
3.Clean the pipettes in use daily
Well, this rule isn’t just for pipettes but for every science equipment in your laboratory. Wipe your pipette with 70% ethanol before starting your experiment every day. This will ensure no residue is still present from the previous day, thus improving the accuracy.
4.Utilize a pipette holder
Any liquid residual present after the experiment in your pipette barrel can lead to corrosion if it moves further inside. To avoid this, store the pipette vertically once done using a pipette holder.
5.Check your pipette for any damage
A regular thorough check of your pipette is necessary to ensure the delivery of accuracy at the time of use. Examine the nose of the barrel and get it immediately serviced if damaged. Another good practice for every science laboratory is to get your pipette serviced every 6 to 12 months. The service should include re-calibration, replacement of parts if required and greasing of moving parts.
6.Make sure the tip fits well
Loose-fitting tips can let air in when drawing up and dispensing the liquid, resulting in inaccurate readings.
7.Be consistent with plunger pressure and speed
Try to apply the same pressure and speed when aspirating and dispensing each sample. Notice when you get the perfect result and be consistent with the steps you followed during that sample.
8.Pull out the pipette in a straight position
Avoid touching the sides of the container and hold the pipette vertically during sample aspiration. Once the aspiration is done, pull the pipette straight out of the liquid. This method is especially crucial when it comes to pipetting small volumes.
We hope these minor yet important tips help you ace your pipetting game! For more information related to laboratory equipment and its workings, reach out to us today!