Serological Pipets Frequently Asked Questions
What are serological pipets used for?
Serological pipets are used for transferring liquids, mixing chemical solutions or cell suspensions, and layering reagents that are composed of different densities. This is done with the help of a pipet controller, filler or bulb. Volume capacities range anywhere from <1mL up to 100mL depending on the brand and model. Serological pipets are made of plastic or glass and are commonly available sterile.
What does graduation mean?
To be able to measure the volume of liquid aspirated and dispensed, serological pipets are marked, or 'graduated', with the numerical volume on the side of the tube. Some serological pipets feature both ascending and descending graduations.
What do the abbreviations TD and TC mean?
TD stands for 'To Deliver' and TC stands for 'To Contain'. In TD-calibrated pipets, a defined amount of liquid is delivered with any residual fluid remaining on the inside walls of the tube being accounted for by previous calibration. In TC-calibrated pipets, the pipette contains a specified volume but dispenses less due to this residual liquid. As such, it is important to blow all of the liquid out of the pipet in order to have the desired volume. Graduated pipets or bulb pipets are common among TD designs, while capillary pipets are common among TC designs.
How do I choose the correct pipet size?
To reduce errors, always use the smallest pipet that is appropriate for the job. A 5mL serological pipet is more accurate than a 10mL pipet when measuring 4.5mL of liquid.
What are the most commonly used sizes of serological pipet?
The most common sizes are 10, 25, and 50mL.
What is the precision of a serological pipet?
Serological pipets are only as precise as their smallest increments, which are typically a few millimeters (0.1mL for those that are 2mL). If your research requires a high level of precision, we recommend combining your laboratory serological pipet with a micropipet.
Which are the most suitable devices for pipetting with serological pipets?
All serological pipets require the use of a pipet dispenser for the transfer of liquids. The pipet dispenser negates the need for a researcher to perform the ancient technique of mouth pipetting. The most basic are rubber suction bulbs, but hand-held electronic pipets are the most widely used for their convenience and accuracy.
Which different types of serological pipet are available?
Serological pipets are typically either plastic, sterile, and disposable or glass, sterilizable and reusable. The most commonly used are those made of sterile, disposable polystyrene.