The proper and efficient operation of your pipette is crucial to the accuracy of your results, and keeps costs down by preventing costly repairs.
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Conducting a 2-minute inspection on your pipette can reveal what’s wrong and help you get the service you need. We’ve included Gilson’s 2-Minute Inspection procedure to guide you along.
Ready to get started?
STEP 1 : Check the Records
Use the serial number to identify the pipette and to determine its age, then check your laboratory records for the date of last servicing.
STEP 2 : General Appearance
Is the operating-rod bent or corroded?
It may have been dropped or been subjected to excessive exposure to corrosive liquid or vapours during decontamination.
Are the volumeter dials incorrectly aligned? Are the number unclear?
Autoclaving changed the appearance and function (the body must not be autoclaved).
Is the tip-ejector corroded or broken?
It may have been subjected to excessive exposure to corrosive liquid or vapours during decontamination.
Is there physical or chemical damage to the tip holder?
It may have received repeated blows, or been dropped or been subjected to excessive exposure to corrosive liquid or vapours during decontamination.
STEP 3 : Check Functions
Large volume adjustment
- Set volume at maximum (i.e. nominal volume) assessing the movement of the friction ring
- Activate the push-button to test movement during aspirate and dispense strokes
Hitching, due to damage to the friction ring
Bent operating rod
Corroded, dirty or scratched piston
Go through the entire range. The settings should correspond to the pipette’s useful volume range (minimum to nominal volume).
Possibly caused by autoclaving.
Incorrect volume setting?
May be caused by misindexing; pipette adjustment screw has been incorrectly reassembled.
- Fit tip and depress tip-ejector button
- Observe function of tip-ejector
- Disassemble tip-ejector
Broken return spring
Not tight enough
STEP 4 : Leak Test
- Fit the pipette tip
- Set volume at maximum (i.e. nominal volume)
- Pre-rinse by aspirating and dispensing wate, several times
- Aspirate water
- Hold the pipette in the vertical position for 20 seconds
- For models P2 to P200, re-immerse in the test liquid; fluid level in tip should remain constant
- Observe if a drop or a leak appears at the orifice of the tip
Are either tip or tip holder leaking?
- The end of the tip holder may be scratched/damaged (mechanical or chemical)
- The tip may fit imporperly due to the use of non-manufacturer tips
- Organic solvent, vapour pressure
STEP 5 : Disassembly and Reassembly
- Eject the tip
- Pull the tip-ejector down
- Unscrew the connecting nut
- Separate the handle from the bottom part
- Remove the piston from the tip-holder
Check to see if the piston surface is corroded, scratched or damaged. Also check the piston seal and o-ring for mechanical damage or chemical attack.
To avoid losing or damaging fragile parts, reassemble the pipette immediately. Be sure to respect the correct order of parts: the piston seal should always be positioned before the O-ring. You should never disassemble the body (handle) of the pipette!
We hope this guide will help you assess your current pipette lineup.
For on-site inspections, preventative maintenance, or to schedule calibration and service, drop us a line. Mandel’s Service team is ready to help keep your lab running smoothly.