Some Tips for Using A Pipette
A pipette is an indispensable tool for experimental operation. For some experts, the important thing is that the experiment has the smallest error and good reproducibility. In order to pipette accuracy, one should pay attention to the correct use of the pipette to avoid small losses.
How to use a pipette:
1. Install the tip
The pipette handle should push down firmly and rotate slightly when the pipette uses. And the wrong operation is hitting the tip hard, which can cause damage to the pipette tip. And the wrong operation is hitting the tip hard, which can cause damage to the pipette tip.
2. Range adjustment
When adjusted the range is from a small range to a large range, it rotates continuously in the direction of the required range, and when the rotation reaches 1/3 of the required range, it returns to the required range.
And operated most of the pipettes in the range of 10-100%, but operation at 10% of the range requires high pipetting skills, so can operate it within 35-100 % of the range.
3. Precise pipetting
Using a pipette, people should rinse the viscous liquid by pre-wetting the tip to achieve precise pipetting. The inner wall of the tip will absorb a layer of liquid to make the surface adsorption saturated and then suck the sample liquid, which is the final volume of the liquid that will be very accurate.
4 Tip rinsing
Repeat aspiration and drainage with the same sample two to three times, and rinse to provide the same contact surface for each subsequent aspiration to ensure the consistency of operation.
At room temperature, tip rinsing can directly improve accuracy; but for samples, with high or low temperatures, tip rinsing will decrease the accuracy of the operation. Please pay special attention.
How to properly use a pipette:
a) For automatic pipette accuracy, not be held in your hand for a long time, and it is best to hang it on a stand or hang it on your hand for a while when not in use
b) When the use of pipette tips is immersed in the angle to absorb liquid, we should try to keep it vertical, and the inclination angle should not exceed 20°
c) After immersing the tip in the liquid for aspiration, we should keep it on the liquid surface for one second and then gently remove the tip. This is especially important for large-capacity pipettes or for aspirating viscous samples.
d) Pipette the liquid at a uniform and continuous suction speed. Control the pipetting speed. If too fast will make spray, liquid, or aerosol directly get into the pipette and contaminate the piston and other parts.
What affects the automatic pipette accuracy?
(1) Suction speed:
It is easy to cause air bubbles in the tip and contaminate the tip;
(2) The volatilization of reagents:
When the reagent with high volatility is sucked, the steam enters the gun head, and the internal pressure increases. As a result, when the liquid is pressed out, the pressure increases, which causes errors;
The room temperature is low, but the hand temperature is high, which makes the air expand, and errors often occur when inhaling the cold solution
The joint between the tip and the gun body, and the long-term wear between the cylinders in the gun, cause errors.
There are more introduces about pipettes: how to use a multi-channel pipette, how to check pipette accuracy precision, etc.