FREE ABT Methods in Toxicology Questions and Answers

Question 1

What is the purpose of the LD50 test in toxicology?

Accepted Answer

To identify the lethal dose for 50% of a test population

Answer

The LD50 (Lethal Dose 50%) test is a standard measure in toxicology used to determine the dose of a substance that is lethal for 50% of a test population. It provides a quantitative estimate of the acute toxicity of a chemical, indicating its short-term poisoning potential. This value helps in classifying substances and setting safety guidelines.

Question 2

Which of the following in vitro methods is commonly used to assess cytotoxicity of chemicals?

Accepted Answer

MTT assay

Answer

The MTT assay is a widely used in vitro method for assessing cell viability and cytotoxicity of chemicals. It measures the metabolic activity of cells, as viable cells convert the yellow MTT tetrazolium dye into a purple formazan product. The intensity of the purple color is directly proportional to the number of living cells, providing a quantitative measure of a chemical's toxic effect on cells.

Question 3

What is the main advantage of using in vitro methods over in vivo methods in toxicology testing?

Accepted Answer

Faster and more controlled environment

Answer

A main advantage of using in vitro methods in toxicology testing is that they are generally faster and conducted in a more controlled environment. These methods allow for high-throughput screening of chemicals, reduced costs, and precise manipulation of experimental conditions, making them efficient for initial hazard identification and mechanistic studies compared to complex in vivo models.

Question 4

What does the Ames test evaluate?

Accepted Answer

Mutagenic potential

Answer

The Ames test is a bacterial assay specifically designed to evaluate the mutagenic potential of chemical compounds. It assesses whether a substance can cause mutations in the DNA of specific strains of Salmonella typhimurium bacteria. A positive result indicates that the chemical may be a mutagen and potentially a carcinogen.

Question 5

Which method is used to detect DNA strand breaks in individual cells?

Accepted Answer

Comet assay

Answer

The Comet assay, also known as single-cell gel electrophoresis, is a sensitive technique used to detect and quantify DNA strand breaks in individual cells. Damaged DNA fragments migrate further in an electric field, creating a characteristic 'comet tail' shape. This assay is valuable for assessing genotoxicity and DNA repair mechanisms.

ABT - American Board of Toxicology Practice Test

ABT - American Board of Toxicology Practice Test

FREE ABT Methods in Toxicology Questions and Answers