Practical 7: Serum Protein Electrophoresis

Question 1

What is electrophoresis?

Answer 1

A method of separating proteins based on their physical properties

Question 2

How is electrophoresis carried out?

Answer 2

Serum is placed on a specific medium and a charge is applied

The net charge and the size and shape of the protein are used to separate and differentiate the various serum proteins

Question 3

What are the two main types of proteins present in serum?

Answer 3

Albumin

Globulins

Question 4

How many peaks are there in SPE?

Answer 4

Five peaks

Question 5

List the peaks in order from left to right

Answer 5

Albumin
a1
a2
B
gamma globulins (y)

Question 6

List the peaks in order of height

Answer 6

Albumin, y-globulins, a2, B, a1

Question 7

How do you interpret an electrophoretogram?
(2)

Answer 7

The height of the peak relates ot the amount of protein

The width of the band relates to the identification of the protein -> narrow = similar group of proteins, wide = dissimilar group of protein

Question 8

How many globulin categories are represented on an electrophoretogram?

Answer 8

a1
a2
B1
B2
gamma

Question 9

How can albumin be broken down in infection?

Answer 9

Albumin can be broken down to provide amino acids for antibodies

Question 10

Why is the albumin band so discrete?

Answer 10

This is because albumin is formed by a non polymorphic gene

Question 11

Is albumin closer to the cathode or anode?

Answer 11

Albumin is closest to the anode

Question 12

What does a thin, high gamma globulin region indicate?

Answer 12

Monoclonal antibody response -> myeloma?

Question 13

What does a broad, high gamma globulin region indicate?

Answer 13

Polyclonal antibody response -> infection

Question 14

Describe the a1 band

Answer 14

Pale band
Very low peak
Bit of a smear
Not narrow

Question 15

Describe the a2 region

Answer 15

Higher and more narrow peak than a1

Question 16

What does a smear result from?

Answer 16

Result of a group of similar but not identical proteins which have similar physical properties such as charge and size

Question 17

Name a molecule found in a1

Answer 17

a1 antitrypsin

Question 18

Name a molecule found in a2

Answer 18

a2 macroglobulin

Question 19

Name a molecule found in B

Answer 19

Trasferrin
B lipoprotein

Question 20

How is an SPE carried out?
(7)

Answer 20

Cellulose acetate strip is placed over solid support

Strip has positive and negative markings

Buffer is used to pass a current of 200V through for 30mins

Ponceau stain -> binds to strip + protein

De-stain with 5% glacial acetic acid

Stain lifted from strip but not proteins

Proteins stained

Question 21

Where might a monoclonal gamma region be seen?

Answer 21

In healthy patients over 60/70

In cancer

Question 22

What is M protein?

Answer 22

Monoclonal protein
Produced by plasma cells

Question 23

Multiple myeloma is seen in what antibodies?

Answer 23

IgG

IgA

Question 24

What type of monoclonal gammopathy is associated with IgM?

Answer 24

Waldenstrom’s macroglobulinemia