Biomarkers, Biomonitoring and Biomarkers of Genotoxicity

Question 1

What is a biomarker?

Answer 1

A sub-lethal biological response to chemicals or radiations that gives a measure of exposure or effect at cellular, tissue, organ, individual, or population level

Question 2

What are the main objectives of biomonitoring?

Answer 2

to identify genotoxic carcinogenic mechanisms by obtaining more precise estimates of the extent to which environmental, lifestyle, and genetic factors contribute to the human cancer burden and possible risk for germ cells,

Question 3

What are DNA adducts?

Answer 3

a type of structural change involving covalent attachments of a chemical or its metabolite to DNA

Question 4

What are common methods to detect DNA strand breaks?

Answer 4

Common methods to detect DNA strand breaks include single cell gel electrophoresis (SCGE), also known as the comet assay

provides a means of quantifying exposure to a wide range of genotoxic chemicals.

Question 5

What does the term ‘tail length’ refer to in comet assays?

Answer 5

refers to the distance of DNA migration from the nucleus, indicating the extent of DNA damage.

Question 6

Define the Olive tail moment in the context of the comet assay.
defined as the product of the tail length and the fraction of total DNA in the tail, providing a measure of DNA damage

Answer 6

defined as the product of the tail length and the fraction of total DNA in the tail, providing a measure of DNA damage

Question 7

What types of sources can be used for DNA extraction in biomonitoring aquatic animals?

Answer 7

Sources for DNA extraction can include blood,
haemolymph,
gill cells,
liver cells,
kidneys,
hearts,
gonads (ovaries and testis),
tissue homogenates