Tips for Pipetting Perfection

A pipette which is also at times called a chemical dropper is a laboratory tool commonly used in chemistry, biology and medicine to transport a set about of liquid. These small devices need to be very accurate and precise as does the user of this device. There are several different kinds of pipettes available and is one laboratory device whose result can vary from person to person since it is a very delicate device.  The problem being that if the plunger is released rapidly or the tip of the pipette is not pre wetted, and even if the tip is not immersed far enough in the liquid then it could cause for the readings to vary. Such common errors should usually be avoided since they tend to affect the outcome of the overall result.

It is necessary to use the correct pipette tip. It is possible to mix and match the pipette and the tip but it is ideally safe to stick with the same brand when the pipette and tips are concerned. There are many different types of tips available and it is important not to get confused while selecting the tip.

It is a good practice to moist the pipette tip prior to use to increase the humidity thus decreasing evaporation. One should carefully examine the tip while dispensing the liquid since it is possible that extra droplets are present on the outer side of the pipette which could mess up your readings. Thus wiping the pipette after a dip is the way to go.

The liquid in question should first be examined since if you immerse the tip too far into the liquid then there are often extra droplets sticking to the outside of the tip. This is the reason you need to wipe the outside gently before dispensing and also take care as to not to touch the tip mouth.

One should remember to use the second stop on the pipettes to dispense the entire volume of liquid. 

It is necessary to pause for a while after aspiration, because after the liquid is drawn up, it takes a while before it is fully done. Thus you need to wait and make sure the process is over before pulling out the tip completely.

One thing to always follow is to pull the pipette straight out, since touching the sides of the container from where liquid is drawn will cause wicking and loss of volume.

The plunger pressure applied should be consistent through out the process.

Transfer of heat from your hands to the pipette can some times be an issue as well hence minimize the handling of the pipette and the tip. It is important to maintain the temperature equilibrium while working with pipettes. 

Report this Page