Precautions for serological pipette

1. Before use: when using the disposable serum pipette, first look at the pipette mark, accuracy grade, scale position, etc. before use, wet the oil stain on the inner wall of the pipette with chromic acid lotion.

Then rinse the residual lotion with tap water and then wash it with distilled water. There shall be no water droplets hanging on the inner wall of the cleaned pipette. Before taking the solution, absorb the water inside and outside the end of the pipette with filter paper, and then wash the pipe wall with the solution to be taken for 2 ~ 3 times to ensure that the concentration of the solution remains unchanged.

2. Liquid suction: hold the upper end of the pipette with the thumb and middle finger of the right hand, and insert the lower mouth of the pipette into the liquid to be sucked. The insertion should not be too shallow or too deep, generally 10 ~ 20mm.

If it is too shallow, it will lead to empty suction. Inhale the solution into the ear washing ball to dirty the solution. If it is too deep, too much solution will stick outside the tube. Hold the ear washing ball with your left hand, empty the ear washing ball first, then connect the ball tip to the upper mouth of the pipette, slowly loosen the flattened ear washing ball, suck the solution into the pipe, first suck about 1 / 3, press the pipe mouth with your right index finger, take it out, hold it horizontally, rotate the pipe to make the solution contact with the upper part of the scale to replace the water in the pipe. The solution is then discharged from the lower opening of the tube and discarded. After repeated washing for 3 times, you can absorb the solution above the scale, and immediately press and hold the nozzle with your right index finger.

3. Adjust the liquid level: lift the disposable serum pipette up from the liquid level, the end of the pipette still rests on the inner wall of the solution container, and the tube body remains upright. Loosen the index finger slightly (sometimes rotate the pipette slightly) to make the solution in the tube flow out slowly from the lower mouth until the bottom of the solution meniscus is tangent to the marking line, and immediately press the tube mouth with the index finger. The droplet against the wall is taken out, removed from the pipette, and then inserted into the container receiving the solution.

4. Liquid discharge: if the container containing the solution is a conical bottle, tilt the conical bottle 30 °, the pipette is vertical, the lower end of the pipe is close to the inner wall of the conical bottle, loosen the index finger slightly, and let the solution flow down the bottle wall slowly. After all the solution flows out, take out the pipette after 15s to make part of the solution attached to the pipe wall flow out. If the pipette is not marked with "blow", the residual solution of the pipette cannot be blown out because this residual solution is not included in the calibration volume of the pipette.