- Micropipette is a measuring device and dispenser.
- The micropipette is used to transfer small amount of liquids.
- Many modern micropipettes have a digital display in the side of the barrel to indicate the volume amount set by the volume control.
- A disposable tip is replaced after use by pressing an ejector button to release the used one.
- The disposable tips are color-coded to match the volumes they are to be used with.
- Micropipette operate by the vacuum generated by the piston-driven air displacement that occurs when the plunger is pressed.
- After the liquid at the tip moves into the vacuum, it can then be transported and released into another container as needed.
- Micropipettes are capable of being accurate and precise, they can become less accurate as a result of user technique and temperature.
- The instrument manufactures advise users to check the calibration at least every 3 months for pharmaceutical industry.
- Micropipettes are two types.
1.
Non- adjustable
or Fixed micropipette. (Volume adjustment is not possible)
2.
Adjustable micropipette. (Volume adjustment is possible)
- The first non- adjustable or fixed micropipette was invented by Dr.Hanns Schmitz of Germany in 1960.
- The biotechnology company Eppendorf obtained the rights to the patent and introduced the micropipette to the rest of the world.
- Henry Lardy and Warren Gilson, along with several others at
the university of Wisconsion – Madison, invented the adjustable micropipette in
1972.
Operation:
1.
Volume
setting :
- Adjust the volume to be required by rotating the plunger.
- Rotate the plunger in clockwise direction to increase the set volume and anticlock wise direction decrease the set volume until the required volume shows in digital display.
- Attach the appropriate tips are as per the range of the micropipette.
2.
Aspirating
Liquid :
- Hold the vessel containing liquid sample to be aspirated with one hand.
- Put the thumb across the plunger.
- Immerse the pipette tip into the liquid to aspirate.
- Allow the plunger to the slide back slowly and wait for approximately 1 or 2 seconds.
- Pull the tip out the liquid slowly.
3.
Discharging
the sample:
- Hold the vessel into which the sample to be dispensed.
- Hold the pipette at an angle to dispense the liquid directly into the tube through press down the plunger slowly.
4.
Ejection
of Tip:
- Eject he tip by firmly pressing down the
tip ejector.
Precaution
during pipette:
- Don’t allow allow any liquid to enter into the pipette.
- Don’t clean the pipette with acetone or aggressive solutions.
- Be sure you use the proper size tip for each pipette.
- When withdrawing liquids with the pipette, always release the plunger slowly.
- Pre rinse the tip before aspirating the liquid by filling and emptying the tip 2 or more times.
