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A Quick Guide to Maintaining Pipettor Accuracy

Maintaining pipettor accuracy is important to insure valid repeatable results in your laboratory. Human error and mistakes do happen, however there are ways of improving accuracy and minimizing possible errors.  Even a precise instrument like adjustable pipettors need maintenance and require proper user techniques in order to perform as efficiently as possible. If you want the best results, then make sure to implement these following pipetting hints.

1) Service Your Pipettes Regularly

Having your pipette taken in for service and calibrated by a professional is important to improve accuracy and the life span of the pipettor. Most pipettor have small moving parts and need to be oiled or greased to run smoothly again. You can either find a local pipettor technician or send your pipettes into companies to get re-calibrated.

2) Place Pipettor in Holders When Not in Use

Keep your pipettors on holders to prevent any possible damage or additional build-up of laboratory substances. This also makes sure your pipettes are organized, easy to find, and keeps them conveniently placed. We offer a variety of pipette stands/racks from Globe Scientific.

3) Only Use Correct Matching Pipette Tips 

Only specific pipette tips are designed for certain types of pipettors. Tips that now don't fit uniformly or properly can cause inaccurate results. Some pipette tips simply won't fit some pipettors because it is not the right size for the tip cone of the actual pipette. When purchasing pipette tips It is best to use tips that are made by the same brand of the pipettor. This will eliminate any compatibility issues between pipette tips and pipettors. Not sure on how to match your pipette tips? Take a look at our guide here. If you are still unsure or are using a different pipettor not made by Globe Scientific you can opt for a universal fitting pipette tip. These can fit most major brands of pipettors.

4) Review Pipetting Techniques with all Laboratory Workers

It is important to review the proper techniques for pipetting in order to get accurate results every time. Some key hints are to pipette in a smooth steady action and keep the pipettor vertical when drawing liquid in. Make sure to pre-rinse the pipette tips with the liquid you are already pipetting for improved accuracy. In order to pre-rinse, you start by aspirating and dispensing the sample two or three times before beginning the experiment. Also, make sure to wipe the pipette down with 70% ethanol to get rid of any dirt or dust before performing any experiments.

5) Test Accuracy of Your Pipettors with a High Precision Scale or Balance

A simple way to ensure accuracy before experiments is to test your pipette using an analytical balance. To start set up your balance and simply place a weighing dish on the scale then tear it using the tear button. Next dispense 100uL of liquid from your adjustable pipettor. Note that 100uL is equal to 1 g. Do this same experiment 10 different times in our to get a enough data to draw conclusions regarding the accuracy. Observe the data and if there happens to be more than a +/- 5% difference, then you know your pipette is not accurate and needs to be taken in for service. (Note: that different amounts of liquid can be used based on the capacity range of your pipettor)

6) Reduce Pipetting fatigue

Errors often happen when the user is experiencing pipetting fatigue after repetitive pipetting. This can then lead to pipette techniques to break down and increase that chances of inaccuracy. In order to ensure better accuracy make sure you have the right tools for the job! Consider purchasing a repeat volume pipettor or electronic pipettors if a certain experiment requires multiple pipetting of the same volume. Another option are 8 and 12 multi-channel pipettors. These are able to aspirate and dispense multiple samples all at once with ease.
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