Graduated pipette tips are an indispensable tool for experimental operations. For top experts, the most important thing is minimal experimental error and good reproducibility. Then we must pay attention to the correct use of the pipette to avoid small losses.
1. Install the tip
The handle of the graduated pipette tip is pressed down firmly and can be turned in small steps if necessary.
Wrong action:
Hit the tip hard. This method can cause damage to the tips and even wear of the pipette handle, affecting its tightness.
2. Scope settings
Please select the correct graduated pipette tip before operation. The pipette can operate in the 10-100% range, but operating in the 10% range requires high pipetting skill, so the 35-100% range is recommended.
Span adjustment:
When adjusting from a small range to a large range, rotate continuously in the direction of the desired range, and return to the desired range after exceeding the desired range by 1/3 turn. When adjusting from a large range to a small range, rotate directly to the desired range.
3. Run
By pre-wetting the tips, viscous liquids can be accurately pipetted. The sample liquid is sucked and expelled first. The inner wall of the tip will absorb a layer of liquid to saturate the surface, and then aspirate the sample liquid, and the final liquid volume will be very accurate.
Repeat the aspiration and drain 2 to 3 times on the same sample, and rinse to provide the same contact surface for each subsequent aspiration to ensure consistent operation.
For samples at room temperature, tip rinsing can help improve accuracy; however, for samples at high or low temperature, tip rinsing can reduce the accuracy of the operation, so users should pay special attention.
4. Tip immersion angle
When inhaling, try to maintain a vertical state, and the inclination angle should not exceed 20°
5. Immersion depth of tip
6. Tip soaking time
After aspirating, stay on the liquid level for a second, then gently remove the tip. This is especially important for large volume pipettes or for sucking viscous samples.
7. Aspiration speed
Pipette continuously at a uniform speed and control the pipetting speed. Too fast will cause liquid spray, liquid or aerosol to rush into the pipette and contaminate parts such as the piston.
8. Discharge and blowout
First press the piston to the first gear to deflate, and then press the second gear to blow air after a short pause.
9. Hand temperature
The pipette should not be held in the hand for long periods of time. It is best to hang it on a stand or on your hand when not in use.
