MLS Laboratory Equipment & Techniques

Question 1

Which piece of laboratory equipment is used to measure the absorbance of a solution at a specific wavelength?

Accepted Answer

Spectrophotometer

Answer

A spectrophotometer is an analytical instrument used to measure the intensity of light absorbed or transmitted by a solution at specific wavelengths. It quantifies the amount of light absorbed, which is directly proportional to the concentration of the analyte in the solution, according to Beer-Lambert's Law. This makes it essential for various quantitative assays in a clinical laboratory, such as measuring enzyme activity or analyte concentrations.

Question 2

Which laboratory technique is used to separate components of a mixture based on their density?

Accepted Answer

Centrifugation

Answer

Centrifugation is a laboratory technique that uses centrifugal force to separate components of a mixture based on their density. By spinning samples at high speeds, denser particles are forced to the bottom of the tube (forming a pellet), while lighter components remain in the supernatant. This technique is widely used to separate blood components (like plasma from red blood cells), cells from culture media, or macromolecules.

Question 3

Which type of pipette is used for highly accurate liquid volume measurements?

Accepted Answer

Micropipette

Answer

Micropipettes are precision instruments designed for highly accurate and reproducible measurement and transfer of very small liquid volumes, typically in the microliter range. They are essential in molecular biology, clinical diagnostics, and other laboratory applications where exact volumes are critical for experimental integrity and reliable results. Their adjustable volume settings and disposable tips ensure precision and prevent cross-contamination.

Question 4

What is the purpose of an autoclave in a clinical laboratory?

Accepted Answer

Sterilize laboratory equipment

Answer

An autoclave is a device that uses high-pressure saturated steam to sterilize laboratory equipment, media, and waste. The intense heat (typically 121°C or 134°C) and pressure effectively kill bacteria, viruses, fungi, and spores, ensuring aseptic conditions. This process is crucial for preventing contamination in experiments, preparing sterile reagents, and safely disposing of biohazardous materials in a clinical laboratory.

Question 5

Which technique is used to separate DNA fragments based on their size?

Accepted Answer

Gel electrophoresis

Answer

Gel electrophoresis is a molecular biology technique used to separate DNA fragments (as well as RNA and proteins) based on their size and electrical charge. DNA, being negatively charged, migrates through a gel matrix towards a positive electrode when an electric current is applied. Smaller fragments move faster and further through the gel pores than larger ones, allowing for their separation and subsequent visualization.

(MLS) Medical Laboratory Scientist Practice Test

(MLS) Medical Laboratory Scientist Practice Test

MLS Laboratory Equipment & Techniques