One. Pipettes are commonly used liquid measuring instruments in biochemical experiments. According to different needs, it is divided into different scales, such as 10mL, 5mL, 2mL, 0.5mL, 0.1mL, etc. First select a pipette with a close scale according to the volume of the solution to be weighed (note: the volume of the pipette must be greater than or equal to the volume to be weighed).
b. Observe the arrangement of the pipette scale numbers, pay attention to whether the scale is from top to bottom or bottom to top, and find the 0 scale value.
C. Hold the ear ball in one hand and the pipette in the other.
First insert the pipette into the liquid level for about 1 cm, squeeze the suction bulb to expel the gas, then plug the upper mouth of the suction tube, slowly loosen the suction bulb, and observe the rise of the liquid level. When the liquid level rises some distance above the zero mark, remove the suction bulb and hold the upper port of the pipette with the index finger of the hand holding the pipette (remember not to use the thumb).
d. Hold the ear ball and put it down, take the filter paper to wipe the liquid on the outer wall of the pipette clean; pick up the reagent bottle, ask the reagent bottle to be at 45° to the table, the pipette head touches the bottle wall and is perpendicular to the table, and slowly relax Index finger and slowly bring the liquid level down to zero. Be careful not to lower the level too quickly.
e. A handheld container is also required when moving to another container. The container is at 45° to the table top. The pipette tip touches the wall and is perpendicular to the tabletop. Relax your index finger and release the volume you want to remove.
F. When it is necessary to release all liquid from the selected pipette, pay attention to whether the pipette needs to be blown. Generally less than 1ml (including 1ml) pipette, when the whole volume needs to be released, use the ear bulb to blow out the remaining solution in the tube to make it reach the required volume. When a pipette with a capacity of 1 ml or more releases all its solution, there is no need to blow air, just rest the pipette head against the wall. It stays for about 15 seconds after all pipette tips are in place. At this time, part of the solution remains in the tube tip, which becomes a dead volume. Insufflation will exceed the required volume.
G. The pipette should be cleaned in time after use, and care should be taken to avoid mixing contaminating reagents.
