What is the difference between Mohr and serological pipette?
The Correct Answer and Explanation is :
Mohr and serological pipettes are both types of laboratory instruments used to measure and transfer liquids, but they differ in terms of design, functionality, and usage.
- Design and Structure:
- Mohr Pipette: The Mohr pipette is a type of graduated pipette with markings along its length. However, unlike the serological pipette, it is not calibrated to allow for the draining of the liquid to the last drop. Mohr pipettes have a set of graduations that stop before the pipette’s tip. This means that liquid is not intended to be delivered from the last graduation down to the tip.
- Serological Pipette: The serological pipette is a longer, graduated pipette that is calibrated to allow the entire liquid to be delivered, including the liquid in the tip. It is usually designed with a wider bore and has markings from the top to the tip. Unlike the Mohr pipette, a serological pipette can be drained completely to deliver all the liquid.
- Functionality:
- Mohr Pipette: Mohr pipettes are typically used when precise volume measurements are needed but without needing to deliver the final drop. For example, when measuring a liquid that requires dispensing a specific volume that doesn’t include the tip, such as when preparing standard solutions.
- Serological Pipette: Serological pipettes are used when precise and complete transfer of liquid is needed. Because these pipettes are designed to deliver the entire volume, including the last drop, they are ideal for titrations or transferring cultures where the exact amount is crucial.
- Usage:
- Mohr Pipette: Commonly used in titration and other applications where volume control is essential but exact final drop measurement isn’t necessary.
- Serological Pipette: Often used in laboratory research and clinical settings, particularly in biology and chemistry, where accuracy and complete liquid transfer are essential.
In summary, the main difference lies in the capability to deliver the last drop of liquid. Mohr pipettes stop before the tip, while serological pipettes allow full delivery, including the tip.