Standard operating procedures for adjustable pipettes

Purpose: To standardize the operation procedures of the equipment and ensure the normal state of the sampler.

Scope of application: The operation of the laboratory sampler.

Operator: the laboratory experimenter.

Steps:

1. Set volume value: Turn the adjustment knob of the sampler and turn the knob counterclockwise to increase the set pipetting volume. Turn the knob clockwise to decrease the set pipetting volume. When adjusting the knob for setting the pipetting volume, do not use excessive force, and pay attention so that the value displayed by the pipette does not exceed its adjustable range.

2. Pre-wash: When a new tip is installed, the tip should be pre-washed, and the liquid should be sucked once and discharged back into the original container.

3. Discharge:

[1] Stick the mouth of the tip to the bottom of the inner wall of the container and keep it inclined at 100 ~ 40 °.

[2] Press the button steadily to the first stop point, wait one second and then press the button to the second stop point to drain the remaining liquid.

[3] While holding down the button, lift the sampler and wipe the tip against the container wall.

[4] Release the button.

[5] Press the tip ejector to remove the tip.

4. Liquid absorption:

[1] Select the appropriate tip to place on the pipette sleeve, twist and press the nozzle slightly so that there is no air gap between it and the sleeve.

[2] Before taking the liquid, the liquid should be balanced at room temperature (15 ℃ -25 ℃).

[3] Press the button to the first stop point, hold the sampler vertically, so that the tip is immersed 2 to 3 mm below the liquid surface, then slowly and smoothly release the button, draw the liquid, wait one second, and then The tip lifts off the liquid surface and stays on the wall for 2-3 seconds, causing the droplets on the outside of the tube tip to slide off.

5. The sampler nozzle is for single use.

Sampler maintenance procedures:

The sampler should be maintained according to the frequency of use, but at least every 3 months, the specific method is as follows:

1. General maintenance can be cleaned with neutral detergent, or 60% isopropanol, then repeatedly washed with distilled water to remove the detergent or isopropanol, and dry. A certain amount of lubricant can be used on the piston after cleaning.

2. If there is serious contamination of liquid into the sampler, the sampler can be disassembled and cleaned. For the specific disassembly steps, please refer to the sampler's manual.

3. High-pressure sterilization. The pipette part of some samplers can be sterilized by high-pressure, but it should be noted that the temperature should not be overtime during sterilization, nor can it be placed under pressure to avoid deformation.

4. The adjustable pipette should be properly erected on the bracket when not in use, away from moisture and corrosive substances.

5. During the pipetting operation, in order to prevent the liquid from entering the sampler sleeve, you must pay attention to: keep the button stable when pressing the button; the sampler must not be reversed; the sampler should not be placed flat when there is liquid in the tip.

6. Check the outer surface of the pipette for dust or dirt before starting work every day, and wipe it off carefully if there is.