Ch2

Question 1

What is a biomarker

Answer 1

a biomolecule that has the ability to play a prime role in different biological and pathological processes or give a specific pharmacological response to a drug

it is a short-term biological marker that can be used as an indicator of a particular disease stage or some other physiological states of an organism.

Question 2

What are the 3 types of biomarkers

Answer 2

predictive - help predict therapeutic response to a specific drug
prognostic - indicate the development of a disease
diagnostic - detects or confirms the presence of a disease or condition of interest, or identifies an individual with a subtype of the disease

Question 3

Types of Molecular biomarkers?

Answer 3

1. Macromolecules: DNA/RNA, proteins
   - wide applications in cancer and viral diseases
   - ex. receptor proteins on normal cells turn into cancer biomarkers
2. Small molecules: products in metabolic pathways which may regulate biological processes
   - ex. cortisol used as stress biomarker
   - continuous monitoring useful for early warning for patients with critical conditions such as kidney, liver or heart disease

Question 4

What body fluids are used as a source for biomarkers?

Answer 4

blood (gold standard), urine, pleural effusion, sweat, cerebrospinal fluid, saliva

Question 5

define transcellular and paracellular, and which fluids receive biomarkers through these methods?

Answer 5

transcellular: diffusion through the plasma membrane of capillary endothelial cells or vesicular transport through the cell (transcytosis)

paracellular: diffusion or advective transport through the space between cells

this is for interstitial fluid, swear and saliva

Question 6

examples of using sweat for diagnostics

Answer 6

limited commercial application, for infant cystic fibrosis, detects chloride concentrations in the sweat

consists of water and electrolytes

Question 7

Examples of saliva for diagnostics

Answer 7

detection of viral diseases, gastric ulcers and cancer, liver disease and tuberculosis

monitor levels of polypeptides, steroids, antibodies, alcohol, and various drugs

growth factors, plays an important role in wound healing and oral health

Question 8

Examples of urine for diagnostics

Answer 8

monitor body homeostasis and some metabolic disease processes
citrate levels are related to several diseases, including kidney dysfunction and prostate cancer

Question 9

examples of CSF

Answer 9

source of brain derived proteins -> neurodegenerative disorders such as alzheimers and parkinsons
- molecular abrations in AD brain are reflected in cerebrospinal fluid.

Question 10

What is lysing

Answer 10

the release of biomarkers from the extracellular vesicles, through mechanical, thermal, or chemical disruption

Question 11

What are some pretreatment procedures for analysis of molecular biomarkers

Answer 11

lysing
purification and target isolation

Question 12

what are the three main groups of biomolecular detection assays

Answer 12

1. biocatalytic assays
2. affinity-based assays
3. nucleic acid hybridization-based assays

Question 13

biomolecular detection assays can be used to detect biomarkers indicative of what 3 conditions?

Answer 13

1. infectious diseases
2. chronic/organ-related diseases
3. cancers

Question 14

which assays are typically used for infectious disease detection?

Answer 14

affinity based and nucleic acid hybridization based

Question 15

which assays are typically used for chronic diseases?

Answer 15

affinity based and biocatalytic

Question 16

which assays are typically used for cancer?

Answer 16

affinity based and hybdridization

Question 17

How do biocatalytic assays work?

Answer 17

reaction of target analyte with recognition element such as enzymes, whole cells, etc, resulting in detectable outcome

Question 18

Explain how glucose detection via glucose oxidase works

Answer 18

oxidation of glucose (target analyte) in the presence of glucose oxidase

O2 and H20 form gluconic acid and hydrogen peroxide

the H2O2 is electrochemically oxidized at the anode of the EC probe, producing a current proportional to the concentration of glucose in the sample

Question 19

explain how cholesterol detection via cholesterol oxidase works

Answer 19

paper based test

consists of cerium oxide NPs

cholesterol oxidase catalyzes oxidation of cholesterol, produces H2O2, forming peroxide complex on the nanoceria surface

induces colour change from white to yellow/orange, quantified by image J on smartphone

Question 20

Explain how uric acid detection works

Answer 20

in the presence of O2, uricase enzyme catalyzes uric acid to produce H2O2.

molybdenum disulfide (MoS2) is also under catalysis, and

ok what on earth is this explanation ma’am (slide 22)

Question 21

How do affinity based assays work?

Answer 21

employ non-reactive approach, in which specific binding interaction between analyte and BRE is converted to a measurable signal by a transducer

Question 22

Why would affinity based assay be used over biocatalytic?

Answer 22

there is a lack of sufficiently selective enzymes for certain analytes. In this case, we would use affinity-based

Question 23

Types of BREs for affinity based assays

Answer 23

antibody based
aptamber based
MIP (molecularly imprinted polymers)

Question 24

what is an antibody :)

Answer 24

uniquely patterned amino acids that can only bind to target antigens with a specific molecular sequence that provides complementary charges and noncovalent bonds

monoclonal and polyclonal, created by lymphocytes

Question 25

how are antibodies created

Answer 25

1. inject animal with specific antigen
2. animals immune system will produce specific antibodies
3. harvested as whole serum
4. typically polyclonal, most antigens are complex structures with multiple epitopes, they result in the production of multiple anitboies

Question 26

why are mABs used over pABs?

Answer 26

mABs are produced in vitro using tissue culture techniques, and are used in cases where all of the antibodies must bind with high affinity to a single epitope