MLS Diagnostic Procedures & Reporting

Question 1

Which diagnostic test is commonly used to detect bacterial infections in the bloodstream?

Accepted Answer

Blood Culture

Answer

A blood culture is the gold standard diagnostic test for detecting bacterial or fungal infections in the bloodstream, a condition known as bacteremia or septicemia. Blood samples are collected and incubated in a nutrient-rich medium to allow any present microorganisms to grow. Positive cultures can then be identified, and their susceptibility to antibiotics can be determined, guiding appropriate treatment.

Question 2

What is the primary purpose of performing a Polymerase Chain Reaction (PCR) test?

Accepted Answer

To amplify DNA for detection of pathogens

Answer

Polymerase Chain Reaction (PCR) is a powerful molecular biology technique used to amplify specific segments of DNA exponentially. This amplification allows for the detection of even minute amounts of genetic material from pathogens like viruses or bacteria, making it invaluable for diagnosing infectious diseases, identifying genetic disorders, and forensic analysis. PCR creates millions of copies of a target DNA sequence, enabling its detection and study.

Question 3

Which of the following tests is used to diagnose tuberculosis (TB)?

Accepted Answer

Mantoux Tuberculin Skin Test (TST)

Answer

The Mantoux Tuberculin Skin Test (TST), also known as a PPD test, is a common diagnostic tool used to screen for latent tuberculosis infection. It involves injecting a small amount of tuberculin purified protein derivative (PPD) into the forearm. A localized immune reaction (induration) observed after 48-72 hours indicates exposure to Mycobacterium tuberculosis, though further tests are needed to confirm active disease.

Question 4

Which diagnostic imaging technique is commonly used to visualize soft tissue structures such as the liver, kidneys, and heart?

Accepted Answer

Ultrasound

Answer

Ultrasound imaging uses high-frequency sound waves to create real-time images of internal body structures. It is particularly effective for visualizing soft tissues and organs like the liver, kidneys, and heart because sound waves reflect differently off various tissue densities. Unlike X-rays, it does not use ionizing radiation and can show movement, blood flow, and organ function dynamically, making it a versatile and safe diagnostic tool.

Question 5

Which laboratory test is commonly used to assess thyroid function?

Accepted Answer

Thyroid-Stimulating Hormone (TSH)

Answer

Thyroid-Stimulating Hormone (TSH) is the primary screening test for assessing thyroid function because it reflects how well the pituitary gland is stimulating the thyroid gland. Elevated TSH levels typically indicate an underactive thyroid (hypothyroidism), while low TSH levels suggest an overactive thyroid (hyperthyroidism). This test provides a sensitive and early indicator of thyroid dysfunction, guiding further diagnostic steps.

(MLS) Medical Laboratory Scientist Practice Test

(MLS) Medical Laboratory Scientist Practice Test

MLS Diagnostic Procedures & Reporting