BACE - Biotechnician Assistant Credentialing Basic Laboratory Equipment Use Questions and Answers

Question 1

A technician needs to accurately transfer 185 µL of a buffer solution.
The lab has P20, P200, and P1000 micropipettes available.
Which micropipette should be used for the highest accuracy and precision?

Accepted Answer

P200

Answer

P1000

Answer

P20

Answer

Any of them will work equally well

Question 2

Before starting a microcentrifuge, a technician places two 1.5 mL tubes containing samples of unequal mass opposite each other in the rotor. What is the most likely consequence of this action?

Accepted Answer

The centrifuge will generate excessive noise and vibration, potentially damaging the unit.

Answer

The samples will not pellet correctly.

Answer

The centrifuge lid will not lock properly.

Answer

The run time will automatically increase to compensate.

Question 3

A biotechnician is preparing to measure the pH of a critical buffer solution. Which of the following is the most important first step to ensure an accurate reading?

Accepted Answer

Calibrating the meter using at least two standard buffers of known pH.

Answer

Wiping the electrode dry with a paper towel after rinsing.

Answer

Ensuring the buffer solution is at exactly 25°C.

Answer

Rinsing the electrode with the buffer solution to be measured.

Question 4

What are the three critical parameters that an autoclave utilizes to achieve sterilization of laboratory equipment and media?

Accepted Answer

High temperature, high pressure, and steam.

Answer

UV radiation, high pressure, and filtration.

Answer

Dry heat, long duration, and vacuum.

Answer

High pressure, low temperature, and chemical disinfectants.

Question 5

When using a spectrophotometer to measure the absorbance of a colored solution, what is the primary purpose of first inserting a 'blank' cuvette containing only the solvent?

Accepted Answer

To calibrate the instrument by setting the absorbance of the solvent to zero.

Answer

To clean the optical pathway of the instrument before the real measurement.

Answer

To verify that the correct wavelength has been selected.

Answer

To set the maximum absorbance reading (100%) for the instrument.

Question 6

A protocol requires a 15-minute incubation of an enzymatic reaction at exactly 37°C. Which of the following is the most critical step when using a standard laboratory water bath for this procedure?

Accepted Answer

Ensuring the water level is high enough to cover the portion of the tube containing the reaction mixture.

Answer

Using a lid on the water bath to prevent evaporation.

Answer

Adding a stir bar to the reaction tube to ensure even heating.

Answer

Placing the tube in the bath immediately after turning the power on.

A technician needs to accurately transfer 185 µL of a buffer solution.The lab has P20, P200, and P1000 micropipettes available.Which micropipette should be used for the highest accuracy and precision?

A technician needs to accurately transfer 185 µL of a buffer solution.
The lab has P20, P200, and P1000 micropipettes available.
Which micropipette should be used for the highest accuracy and precision?