An air displacement pipette is a common laboratory tool used to handle a measured volume of liquid between 1 µl to 1000 µl (1 ml). Due to its high accuracy, this laboratory tool is commonly used in standard pipetting applications. An air displacement pipette has six main components (plunger button, tip ejector button, volume adjustment dial, digital volume indicator, shaft and the attachment point for the disposable tip) and is available in different models. It is important to note that the piston is a permanent part of the pipette. In a nutshell, piston driven air displacement makes these pipettes work. The piston inside the air tight sleeve descends and forces out a volume of air when the plunger button is depressed. Upon releasing the plunger button, a partial vacuum is created in the space vacated by the piston.
Glass and Plastic Droppers The original pipette was made of glass. It is more commonly used in chemistry with aqueous solutions. There are two types of these—the volumetric pipette, which typically has a large bulb and is calibrated for a single volume, and Mohr pipettes, typically straight-walled and graduated for different volumes. In the beginning, all pipettes were made of glass. However, over the years plastic pipettes have become increasingly popular. The biggest drawback of glassware is breakage. Accidental breakage results in loss of valuable product, harmful spillages, contamination, and even potential injuries to consumers. But don’t rule out plastic! There are a few big advantages to using plastic pipettes in your packaging. The main reasons are its unbreakable nature, cost, and compatibility with common laboratory chemicals.
Yes. All Capp pipettes have an ultimate chemical resistance. The metallic parts of Capp mechanical pipettes are covered with a protective anodized layer, which ensures their chemical compatibility. When working with evaporating or corrosive substances, Capp recommends to use ExpellPlusTM filter tips. Having premium filters with controlled pore size and no use of additives, ExpellPlusTM filter tips will ensure the most ultimate corrosion protection for your pipette.
The filter pipette tips serve the basic purpose of protecting pipettes from aerosols and aspirating volatile or viscous solutions, avoiding contamination and damage of the pipette. The filter pipette tips are pre-sterilized, and are fitted inside the proximal part of the pipette tip. Filter pipette tips also aid in carrying out experiment by new researchers. Inexperience researchers accidentally aspirate the reagent directly into the pipette, resulting in the contamination of the pipette. Filter pipette tips can be fitted to the pipettes as it is more cost-effective if one has to just discard the tip rather than sending the pipette for repair.
Air Displacement Micropipette: This type of micropipette works on the air displacement principle. Dispensing solvents accurately with an air displacement micropipette can be challenging if not done with the right pipetting technique. Solvents such as acetone and acetonitrile possess a high vapour pressure and thus evaporate quickly. As soon as the liquid is aspirated into the pipette, evaporation begins.
Open the pipette and place the contaminated parts in a strong detergent or cleaning solution. Rinse several times with distilled water and allow to dry. Decontamination should always be followed by confirming that radioactivity has been reduced to an acceptable level.
By spraying or wiping the exterior of the instrument, the outside of the pipette can be easily cleaned. To ensure full sterilization, let the cleaning solution sit on the pipette for 10-12 minutes before wiping it off.
Press the plunger button to push the piston downward. This action displaces a volume of air equal to the required volume of liquid. Smoothly press the plunger button to the first stop position while holding the pipette in a nearly vertical position.
Both pipette types have a piston that moves in a cylinder or capillary. In air displacement pipettes, a certain volume of air remains between the piston and the liquid. In positive displacement pipetting, the piston is in direct contact with the liquid.
When using an air displacement pipette, the reverse mode technique is the preferred method when pipetting viscous liquids.” With reverse mode pipetting you will aspirate the blow out volume but will not dispense it all out since you are only pushing the plunger to the first stop.
