Scientific investigations and clinical work frequently require precise measurements. Pipettes offer a convenient way to measure the variety of liquids that can provide valuable — and actionable — results.
Here's what you need to know about the different types of pipettes, plus guidance on ways to use and care for pipettes.
Several types of pipets are available for typical, everyday use. However, these devices do have their differences.
Serological pipettes transfers liquids measured in milliliters, are calibrated to the tip of the pipette, and measures liquids for dispersion and aspiration. Serological pipettes such as Corning® Falcon® Individually Wrapped Serological Pipets and Corning Stripette™ Serological Pipets, are useful for routine cell culture and transferring cell colonies post-harvest. They can also mix reagents, cell suspensions, cell culture media or chemical solutions. Clinically, serological pipettes are frequently used for urinalysis, blood banking, immunology, and hematology.
Also called a bulb or belly pipette, a volumetric pipette like the Corning PYREX® Reusable Glass Volumetric Pipet delivers specific amounts of solution via free drainage. These pipettes are routinely used to create serial and stock solutions. They're also used for titrations and volumetric analysis. Volumetric pipettes are often the go-to pipette for working with cell culture media, analytical solutions, solvents, and organic chemicals.
Also called a Mohr burette, this pipette's calibration marks don't extend to the tip, and it isn't as accurate as a volumetric pipette. However, Mohr pipettes, like the Corning PYREX Reusable Glass Measuring Pipets offer bidirectional graduation, like a serological pipette. Typically made of glass, they have a tap on the tip to control liquid flow. Mohr pipettes are also used with titrations and clinical analyses.
Also called Pasteur or teat pipettes, these disposable, plastic devices transfer small amounts of liquid without risk of cross-contamination. Transfer pipettes, such as Corning's Falcon® Transfer Pipets or Gosselin™ Transfer Pipets can have graduated or smooth barrels and are used for rough measurements. Transfer pipettes are often used with urinalysis, hematology, immunology, and blood banking.
Aspirating pipettes, such as the Corning Costar® Aspirating Pipets, allow for the removal or aspiration of liquid from a vessel without volume measurement. These pipettes may be used when accuracy isn't required. Although aspirating pipettes may be open at both the top and bottom, it's important to attached the pipette to vacuum-aspirator like Corning Stripettor Pro pipet controller.
In addition to standard types of pipettes, advanced pipettor versions are available. These pipettes are frequently used for more specific tasks.
With this pipette, a small cushion of air exists between the pipettor piston and the liquid you're measuring. Calibrating the piston can ensure the most accurate delivery of specific liquid amounts. Consequently, these highly accurate pipettors work well with a range of typical pipette functions.
Generally, air displacement pipettors, like Corning Lambda™ EliteTouch™ pipettors, deliver small doses of aqueous or non-viscous liquids that must be measured with pinpoint accuracy. Be aware that temperature, atmospheric pressure, and liquid viscosity and density can significantly affect this pipette's performance.
Unlike air displacement pipettors, positive displacement pipettors, such as Corning Step-R™ Repeating Pipettors, do not use air pressure for liquid delivery. Instead, these pipette pistons sit in a disposable syringe. The syringe ensures the pipette isn't vulnerable to external factors, such as temperature or air pressure. The absence of air means this highly accurate pipette can dispense liquids that are volatile, hazardous, or highly viscous, such as fats, resins, protein solutions, hydrogels (like Matrigel® and collagen) or oils.
Using pipettes every day can lead to discomfort and injury that could impact your workflow if you aren't maintaining the proper form. Pipette ergonomics — from proper posture to well-designed equipment — can help you avoid these problems.
To set yourself up for success, you should consistently practice good posture:
Advanced pipettes need daily maintenance to safeguard their performance and accuracy. Follow these five steps to ensure pipette longevity and the validity of your work.
Choosing the right pipette for your task, maintaining proper ergonomics when using pipettes, and following a consistent maintenance schedule will help you achieve the best possible performance from all pipette varieties.
