BACE Basic Laboratory Equipment Use 2

Question 1

What is the correct procedure for calibrating a micropipette before use?

Accepted Answer

Pipette a known volume of water and weigh it on an analytical balance to verify accuracy

Answer

Gravimetric calibration — pipetting water and weighing it — uses the known density of water (1.0 g/mL) to verify that the delivered volume matches the set volume.

Question 2

A centrifuge rotor becomes unbalanced during a spin. What is the most immediate risk?

Accepted Answer

Mechanical failure, rotor damage, or injury from rotor failure

Answer

An unbalanced rotor generates enormous centrifugal forces that can cause catastrophic rotor failure, potentially destroying the centrifuge and injuring nearby personnel.

Question 3

Which type of balance should be used when accurately weighing 50 mg of a reagent for a critical buffer preparation?

Accepted Answer

An analytical balance with 0.0001 g (0.1 mg) readability

Answer

An analytical balance with 0.1 mg readability provides the precision needed for accurately measuring small quantities like 50 mg.

Question 4

What is the proper disposal procedure for used sharps (needles, scalpel blades) in a biotechnology laboratory?

Accepted Answer

Dispose in a rigid, puncture-resistant sharps container

Answer

Sharps must be disposed of in rigid, puncture-resistant sharps containers to prevent needlestick injuries and comply with OSHA bloodborne pathogen standards.

Question 5

When using a vortex mixer, what is the appropriate technique for mixing a small volume (100 µL) in a microcentrifuge tube?

Accepted Answer

Press the tube bottom against the vortex pad at a slight angle at medium-low speed

Answer

For small volumes, pressing the tube bottom onto the vortex pad at an angle at medium speed creates a whirlpool inside the tube without risk of tube breakage or splashing.

BACE - Biotechnician Assistant Credentialing Exam Practice Test

BACE - Biotechnician Assistant Credentialing Exam Practice Test

BACE Basic Laboratory Equipment Use 2