Functioning and Maintenance of Micropipettes

2.2   MICROPIPETTES :

DETAILS:        

     

	Adjustable 10- 100 µl ( No. 5)	500 µl ( No. 8)	50 µl, ( No. 9)	5 µl (No.11)
Name of Company	Transferpette	Transferpette	Fin Pipette	Fin Pipette
Model No.	05Z6486	09U8094	0047	M01451
Record Maintained in	DF-16	DF-16	DF-16	DF-16

PURPOSE: Micropipettes are used to measure and deliver reagents in various diagnostic and research techniques of Microbiology.

LOCATION – Virology Laboratory

OPERATION

FILLING:

• Make sure tip is securely attached.
• Hold pipette upright.
• When aspirating, try to keep the tip at a constant depth below the surface of the liquid.
• Guide control button slowly and smoothly.
• When pipetting viscous liquid (e.g. whole blood) leave the tip in the liquid for 1-2 seconds after aspirating before withdrawing it.
• After liquid is in the tip, never lay the pipette on its side.

DISPENSING:

• Hold the tip at an angle, against the inside wall of the vessel/tube if possible.
• Guide control button slowly and smoothly.

TESTING PIPETTING ACCURACY:

·       Following procedure can be used to test the pipette and how accurately it measures volume. Water is used because the weight of 1µl of water is 1µg

·       Inhouse Calibration: Using the reverse pipetting technique, pipette 10 replicate of Distilled water and record the weight (100µl of water should weigh 0.1000

• grams). Reverse pipetting can be done with a manual pipette by pressing the control button slightly past the first stop when aspirating, taking up more liquid than will be dispensed, then pressing control button only to the first stop when dispensing. A small volume will remain in the tip after dispensing.   
• Calculate the mean, standard deviation.

MAINTENANCE:

• Micropipettes are cleaned with spirit swab or 1% Na hypochlorite swab before and after work.
• In house Calibration is done every 3 months by method described in testing pipetting Accuracy.

RESPONSIBILITY – Laboratory technicians

SAFETY PRECAUTIONS:

• Dispense infectious fluids/ harmful reagents carefully to avoid spills and production of aerosols and droplets.

REVIEW, RECORDS, REMARKS&RECOMMENDATIONS

• DF 16 Calibration file

REFERENCE –

• NACO, Manual on quality standards for HIV testing laboratories, Mar. 2007; Annexure X; Page: 120 -121