L2-3 - Plasma Proteins

Question 1

What is the difference between serum and plasma?

Answer 1

Serum is the fluid remaining after blood clots

Plasma is the fluid that holds blood cells in suspension, and is produced after centrifuging with an anti-coagulant

Question 2

Where are most plasma proteins produced? What is the exception to this?

Answer 2

Liver

Immunoglobulins

Question 3

What are the main functions of albumin?

Answer 3

Osmotic pressure regulation, transport

Question 4

In what circumstances would testing albumin levels be considered?

Answer 4

Signs of liver or kidney disease, pregnancy, injury/trauma, infection/inflammation

Question 5

What could a high albumin level indicate?

Answer 5

Dehydration or drugs (androgens, anabolic steroids etc.)

Question 6

Give 3 states a low albumin level could indicate

Answer 6

Liver disease, nephritic syndrome, acute phase response, inflammation, protein maldigestion, malabsorption or loss

Question 7

What is haptoglobin a good indicator of?

Answer 7

Haemolytic anaemia

Question 8

What would a low haptoglobin and high reticulocyte indicate?

Answer 8

Haemolytic anaemia

Question 9

What type of protein is C-reactive protein (CRP)?

Answer 9

Acute phase protein

Question 10

What affects the synthesis of transferrin?

What is this a good indicator of?

Answer 10

Synthesis increases in low iron levels

Iron deficiency anaemia

Question 11

What is special about troponin in terms of what it can be a marker for?

Answer 11

Its subunits have different structures depending on location - skeletal or cardiac muscle

This allows for cardiac specific tests

Question 12

What are the groups seen in plasma protein electrophoresis?

Answer 12

Albumin
Alpha1 (e.g. antitrypsin)
Alpha2 (e.g. haptoglobin)
Beta (e.g. transferrin)
Gamma (Ig)

Question 13

What does single radial immunodiffusion (SRID) measure?

Answer 13

Initial protein concentration of sample

Question 14

How does single radial immunodiffusion (SRID) work?

3 steps

Answer 14

1. Sample is put into a well in agarose mixed with antibodies
2. The proteins diffuse out and form complexes with the antibodies
3. They hit a certain concentration where insoluble complexes form and diffusion stops

Question 15

What is the difference between the sandwich and indirect ELISA?

Answer 15

Sandwich - detects antigen, wells are coated in antibodies

Indirect - detects antibodies, wells are coated in antigen