Introduction to the correct operation and precautions of pipettes

Introduction to the correct operation and precautions of pipettes

Many people who use pipettes for the first time always think that the operation of pipettes is very simple, but they are not. The operation of the pipette is the first step of the scientific experiment. It is a very basic experimental operation, but most people are biased about the operation of the pipette. In fact, the operation of the pipette is a lot of knowledge. You may wish to ask yourself a few questions, you can see whether your operation is biased.

1. Have you ever sucked liquid back into the piston during your operation?

2. Do you take care to ensure that there is no liquid on the outer wall of the nozzle when pipetting?

3. After using the pipette, have you adjusted the pipette volume to the maximum value?

4. After using the pipette, have you placed the pipette flat on the table?

5. Does the pipette operate in the same way when moving viscous liquids and general liquids?

6. How many pipetting methods does the pipette have?

Pipette use and maintenance

Set capacity: When setting the required capacity, it should be adjusted to 1/4 turn greater than the set capacity value, and then adjusted to the set value, so that the mechanical gap can be eliminated and the set value is accurate, that is, the capacity is adjusted Rotate the button more than 1/4 turn of the target capacity value, and then turn it down to the set value.

Aspiration operation:

1. Connect the proper nozzle;

2. Press the control button to the first gear;

3. Put the pipette nozzle vertically into the liquid surface 1-6mm (depending on the capacity of the pipette);

A pipette with a capacity of 0.1-10ul enters 1-2mm below the liquid surface

Pipette with 2-200ul capacity enters 2-3mm below the liquid surface

Pipette with 1-5ml capacity enters 3 -6mm below the liquid surface

Note: To make the measurement accurate, the nozzle can be pre-washed 3 times, that is, the liquid is repeatedly sucked and discharged 3 times.

4. Slowly slide the control button back to its original position; ---! ! !

5. Wait for 1-3 seconds before the pipette removes the liquid;

Pause below 1000ul for 1 second

5-10ml pauses for 2-3 seconds.

6. Slowly take out the nozzle to ensure that there is no liquid on the outer wall of the nozzle.

Discharge operation:

1. Hold the suction nozzle against the inner wall of the volume at a certain angle;

2. Slowly press the control button to the first gear and wait for about 1-3 seconds;

3. During the process of pressing the control button to the second gear, the suction nozzle will drain out the remaining liquid;

4. Slow release control button;

5. Press the ejection key to eject the nozzle.

Maintenance:

1. If the liquid accidentally enters the piston chamber, the pollutants should be removed in time;

2. After using the pipette, adjust the pipette range to the maximum value, and place the pipette vertically on the pipette rack;

3. According to the frequency of use, all pipettes should be washed regularly with soapy water or disinfected with 60% isopropyl alcohol, and then double

Wash and dry with distilled water;

4. Avoid placing at a higher temperature to prevent liquid leakage or inaccuracy caused by deformation;

5. Find professionals to deal with problems in time.

Precautions

1. Use the pipette correctly to aspirate and discharge liquid to achieve high accuracy. Pay special attention to the 2) and 3) operation of liquid drainage;

2. When the pipette nozzle has liquid, do not place the pipette horizontally or upside down to prevent the liquid from flowing into the piston chamber and corroding the pipette piston;

3. The usual method to check whether there is liquid leakage: stop in the liquid for 1-3 seconds after absorbing the liquid and observe whether the liquid level in the tip drops; if the liquid level drops, first check whether there is any problem with the tip. The liquid level still drops after the tip indicates that there is a problem with the piston assembly, and you should find a professional maintenance person to repair it.

4. Pipettes requiring high-temperature sterilization should first be checked whether the pipette used is suitable for high-temperature sterilization before processing.