Matters needing attention in pipette maintenance

1.If it is not used for a long time, adjust the range of the pipette gun to the maximum scale to make the spring in a relaxed state to protect the spring. Not paying attention to this point will easily cause the piston to fail to rebound.

2. If the pipette needs to be used every day, it is recommended to clean and calibrate it every three months. It can be washed with soapy water or sterilized ethanol, then washed with distilled water, and allowed to dry naturally.

3. Steps to clean the pipette: (as follows)

(1) Disassemble the pipette according to the instructions.

(2) Check and wipe dust and stains.

(3) It can only be wiped with 70% ethanol. The nozzle connector and the ejector can be soaked in soapy water or isopropanol solution for two hours. For models with replacement filter elements, replace the dirty filter elements in time to ensure the cleanliness of the cavity.

(4) Coat the pistons, O-rings and springs with silicone oil (no Vaseline with silicone oil).

(5) Install and restore the pipette.

Note: The cleaned pipette needs to be calibrated.

4. Calibration steps

(1) Temperature requirements: Pipette calibration must be performed at room temperature (25+/-2℃).

(2) Refer to the operating instructions of the pipette, different scales of 10000\5000\1000\200ul must be calibrated separately.

(3) Eliminate the bubbles in the pipetting head, and select the scale that needs to be calibrated.

(4) Place an empty container on an electronic balance with an accuracy of 0.1 mg and peel it.

(5) Press the add liquid key, add water to the empty container and weigh, and record the reading.

(6) According to the national standard, the pipette calibration adopts the "three-point test (100%, 50% and 10% of the maximum range), six times per point" rule, and the supplier usually chooses two rules: one is Simple calibration, that is, two-point test (100% and 10% of the maximum range), four times per point; the second is strict calibration, which is three-point test (100%, 50% and 10% of the maximum range), each point ten times. The user selects a rule according to his actual needs and enters the calculation link after completing the test. (Adjust according to the absolute difference between the average value and the actual value, use a tool to tighten the tightness of the spring buckle)

5. Before high temperature disinfection, make sure that the pipette can adapt to high temperature.

6. Carry out by repeating the method of weighing distilled water several times.

7. Check if there is any leakage when using. In the method, suck the liquid and place it vertically in the air for a few seconds to see if the liquid level drops. If it leaks, the reasons are roughly as follows:

(1) Whether the tip of the gun matches;

(2) Whether the spring piston is normal;

(3) If it is a volatile liquid (as in many organic solvents), it may be a problem of saturated vapor pressure. The liquid can be pipetted several times before pipetting.