Correct use method and steps of serological pipette

The serological pipette, also known as disposable pipette, is mainly used to accurately measure a certain volume of liquid, which should be used together with a suitable pipette. Pipette is a measuring device used to accurately transfer a certain volume of solution. The pipette is a measuring instrument, which is only used to measure the volume of the solution it emits. It is a long and thin glass tube with a large expansion in the middle. Its lower end is in the shape of a sharp mouth, and the upper pipe neck is engraved with a marking line, which is a sign of the exact volume to be moved.

Correct use method and steps of serum pipette:

1. Before use: When using the pipette, first look at the pipette mark, accuracy level, scale mark position, etc.

2. Aspiration: Hold the upper end of the pipette with the thumb and middle finger of your right hand, and insert the lower mouth of the pipette into the solution to be sucked. The insertion should not be too shallow or too deep, usually 10~20mm. If it is too shallow, it will cause suction. Aspiration of the solution into the ear wash ball will contaminate the solution. If it is too deep, it will stick too much solution outside the tube. Take the ear wash ball with the left hand, connect it to the upper mouth of the tube and slowly inhale the solution. First inhale about 1/3 of the volume of the tube. Press the tube mouth with the index finger of the right hand, take it out, hold it horizontally, and rotate the tube to make the solution contact the part above the scale to replace the water on the inner wall. Then discharge the solution from the lower mouth of the tube and discard it. After repeated washing for three times, you can absorb the solution to about 5mm above the scale. Immediately press the tube mouth with the index finger of the right hand.

3. Adjust the liquid level: lift the pipette up and away from the liquid level, wipe off the liquid on the outer wall of the pipette with filter paper, the end of the tube rests against the inner wall of the solution container, the tube body remains vertical, slightly relax the index finger to make the solution in the tube slowly flow out from the lower mouth, until the bottom of the meniscus of the solution is tangent to the marking, and immediately press the tube mouth with the index finger. Remove the liquid drop against the wall, remove it from the pipette, and insert it into the vessel receiving the solution.

4. Discharge of solution: If the vessel to receive the solution is a conical flask, the conical flask should be tilted 30 °. The disposable pipette should be vertical. The lower end of the tube should be close to the inner wall of the conical flask. Loosen the index finger and let the solution slowly flow down the bottle wall. When the liquid level drops to the discharge head, the tube contacts the inner wall of the bottle for about 15 seconds, and then remove the pipette. A small amount of solution left at the end of the tube should not be forced to flow out, Because the volume of solution retained at the end has been taken into account.