CBE cortisol/calcium practicals

Question 1

What are binding assays

Answer 1

analyte is assessed by its ability to bind:

Question 2

types of binding assays

Answer 2

1. ligand
2. receptor

Question 3

steps of ELISA immunoassay

Answer 3

1. coating: antigen-protein coat the wall
2. detergent wash excess conjugate
3. proteins like BSA will be used to fill the gaps
4. MOST IMPORTANT - standard/sample cortisol (antigen) and cortisol antibodies will be put in the well
5. The more cortisol antigen put in, the less cortisol antibodies that are open to bind to the antigen on the wall
6. An enyzme binding the antibody will be added in
7. the subtrate of the enzyme is added, the more enzyme, the more intense colour.

The more cortisol put in, the less intense colour

Question 4

types of immunoassays

Answer 4

homogeneous: no separation step
heterogeneous:
- depends on which bind assay it is
separate free/bound binder.
separate free/bound ligand.

Question 5

What kind of immunoassay is ELISA?

Answer 5

enzyme-linked

Question 6

evaluation of ELISA results

Answer 6

1. accuracy
2. parallelism (dilution experiments)
3. precision (replicate experiments)

Question 7

forms of calcium in blood

Answer 7

1. calcium complexed: with phosphate, citrate
2. free/ionised: regulated by PTH
3. albumin-bound: changes with albumin concentration

Question 8

acidaemia and alkaemia: changes in H+ and Ca2+

Answer 8

in alkaemia, Ca2+ tends to bind more with albumin
in acidaemia H+ displace Ca2+

Question 9

total calcium levels and albumin levels

Answer 9

if albumin level below reference range, the calcium level will add.

Question 10

multiple myeloma and hypercalcaemia

Answer 10

malignant proliferation of plasma cells in the bone marrow:
the cells will activate osteoclast precursors through RANKL-RANK interaction
decalcification of osteoid (bone resorption) - hypercalcaemia
bone weakness

Question 11

what is multiple myeloma

Answer 11

a cancer in the bone marrow that affects plasma cells
The plasma cells will produce many monoclonal immunoglobulins.