Micropipette

Micropipette is a laboratory tool, commonly used in Quality control department (Microbiology, Virology, Chemical).

• 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.  
•  Hold the pipette with hand.
• 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.