Which of the following is a reason that 'mark to mark' pipettes have helped with biocontainment?

• A. They allow for faster pipetting, increasing laboratory throughput.
• B. They are made of disposable plastic, preventing cross-contamination.
• C. They automatically sterilize liquids during transfer.
• D. They reduce the need to blow out the last drop, minimizing aerosol generation.

Answer: (D)

Verified step by step guidance

1. Understand the concept of 'mark to mark' pipettes: These pipettes are designed to deliver a precise volume of liquid between two graduation marks without the need to expel the last drop forcibly.
2. Recognize the importance of minimizing aerosol generation in biocontainment: Aerosols can carry infectious agents and pose a risk of contamination or exposure in the laboratory environment.
3. Analyze how 'mark to mark' pipettes reduce aerosol generation: Since they do not require blowing out the last drop, they limit the formation of aerosols that typically occur when liquid is forcefully expelled.
4. Compare this feature to other options: Faster pipetting or disposable materials may improve efficiency or reduce cross-contamination, but they do not directly address aerosol generation, which is critical for biocontainment.
5. Conclude that the key benefit of 'mark to mark' pipettes in biocontainment is their ability to reduce aerosol formation by eliminating the need to blow out the last drop, thereby enhancing laboratory safety.