Transfer pipettes serve the scientific community's need to move liquids between containers or onto microscope slides. Size and quality vary greatly, from small, cheap, plastic transfer pipettes at the high-school level to highly precise glass pipettes with separate bulbs seen in professional laboratories. Regardless of its construct, using a transfer pipette is a simple task once the user gets accustomed to the procedure.
Attach the pipette bulb to the end of the pipette, if necessary. This type of pipette is usually made of glass. Some plastic transfer pipettes have unibody construction with the bulb and pipette combined. Ensure the bulb is seated firmly over the end of the pipette without pushing too hard. Excess force can shatter the glass pipette and lodge glass shrapnel in the user's hand.
Squeeze the bulb to evacuate the air. The more air you evacuate from the bulb, the greater the volume of liquid you can draw into the transfer pipette.
Immerse the narrow end of the transfer pipette assembly into the liquid. Make sure the pipette is deep enough to compensate for the drop in volume associated with the pipette's uptake.
Release the bulb slowly, drawing up the liquid into the pipette. If you need to measure the volume of liquid, watch as the liquid is drawn up and discontinue the bulb release when the volume reaches the appropriate level.
Squeeze the bulb again to evacuate the liquid into an appropriate receptacle or slide.
Bulb sizes are scaled to match pipette sizes. Using an inappropriately sized bulb can cause loss of suction, liquid entering the bulb or insufficient suction.
Attach and remove pipette bulbs with caution and patience. Glass transfer pipettes are fragile and break easily. Use only clean and dry transfer pipettes to avoid unwanted contamination or chemical reactions.