Tennessee Wastewater Operator Practice Exam

What type of pipette has a frosted band indicating that the remaining liquid should be blown out?

1. Mohr pipette

2. Serological pipette

3. Graduated pipette

4. Transfer pipette

The correct answer is: Serological pipette

The serological pipette is specifically designed for transferring fluids and has a frosted band near the top that indicates the user should blow out the remaining liquid. This design feature ensures that the last drop of liquid is delivered, which is crucial when precise measurements are needed for experiments or analysis. In terms of functionality, serological pipettes are often used in laboratory settings for cell and tissue culture applications where accurate volume measurements are vital. The frosted band signals the operator to ensure complete liquid transfer, thereby enhancing the accuracy of measurements. Other types of pipettes serve different purposes. The Mohr pipette, for example, is a type of graduated pipette that is used for delivering specific measured volumes. However, it does not have the frosted band indicating that the remaining liquid should be blown out; rather, it allows for a more controlled dispensing of liquid. Graduated pipettes and transfer pipettes also have unique functions and designs that do not include the blow-out feature associated with serological pipettes.