L6 - Measurement of drug concentration

Question 1

Concentration

Answer 1

• relies on knowing the molecular weight of the substance

- SI unit is MOLAR

Question 2

Activity

Answer 2

• used where the molecular weight of a substance is not known with any certainty e.g. a protein
• the amount of protein present can be expressed in terms of “units of activity” as measured in some form of bioassay

Question 3

The main techniques to measure the concentration of drug in the biological fluid

Answer 3

• Radioimmunoassay
• ELISA
• Bioassay

Question 4

Radioimmunoassay

Answer 4

the amount of radioactivity detected is inversely proportional to the amount of hormone in the sample

Question 5

How many antibodies are utilized in ELISA?

Answer 5

2 (primary and secondary) - secondary antibody is attached to an enzyme

Question 6

What can ELISA use to detect?

Answer 6

the presence of an antigen (hormone) or an antibody (e.g. HIV test)

Question 7

Non-competitive ELISA to detect antibody

Answer 7

coloured products produced in the presence of primary antibodies

Question 8

Competitive ELSA to detect antibody

Answer 8

coloured products produced in the absence of primary antibodies

Question 9

The results of ELISA’s can be quantified by..

Answer 9

measure the colour density of the finished sample

Question 10

The “amount” of colour is proportional to.. (ELISA)

Answer 10

the amount of enzyme-linked secondary antibody AND t to the time the substrate is incubated for

Question 11

What causes the colour change in the sample?

Answer 11

The enzyme converts the colourless substrate into coloured products

Question 12

In bioassay, the biological activity of a drug in a sample is determined by…

Answer 12

comparing the response produced by that sample to that of a Standard Preparation of known biological activity in a standard bioassay

Question 13

2 + 2 Bioassay

Answer 13

it is to determine the relative potency of 2 drugs