A 39-year-old man with untreated HIV infection has night sweats and enlarged lymph nodes. Results: total protein 9.4 g/dL [94 g/L] (reference 6.4-8.3), albumin 3.2 g/dL [32 g/L] (reference 3.5-5.0). Serum protein electrophoresis shows a broad, diffuse increase across the whole gamma zone, with no sharp band. Immunofixation shows diffuse staining in the IgG, IgA, kappa and lambda lanes, with no discrete band in any lane. What are the albumin/globulin (A/G) ratio and the electrophoresis pattern?

A/G 0.52; polyclonal gammopathy

A/G 0.52; monoclonal gammopathy

A/G 1.94; polyclonal gammopathy

A/G 0.34; polyclonal gammopathy

After serum protein electrophoresis shows a possible monoclonal band, immunofixation is performed mainly to:

Identify its heavy and light chain types

Calculate the free light chain ratio

Measure its concentration in g/dL

Measure total IgG, IgA and IgM levels

Proteins: test procedures (electrophoresis, immunofixation)

15 ASCP MLS practice questions on Proteins: test procedures (electrophoresis, immunofixation), part of Chemistry. The first 15 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A 39-year-old man with untreated HIV infection has night sweats and enlarged lymph nodes. Results: total protein 9.4 g/dL [94 g/L] (reference 6.4-8.3), albumin 3.2 g/dL [32 g/L] (reference 3.5-5.0). Serum protein electrophoresis shows a broad, diffuse increase across the whole gamma zone, with no sharp band. Immunofixation shows diffuse staining in the IgG, IgA, kappa and lambda lanes, with no discrete band in any lane. What are the albumin/globulin (A/G) ratio and the electrophoresis pattern?
1. AA/G 0.52; monoclonal gammopathy
2. BA/G 1.94; polyclonal gammopathy
3. CA/G 0.34; polyclonal gammopathy
4. DA/G 0.52; polyclonal gammopathy
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Answer: D · A/G 0.52; polyclonal gammopathy
Globulin = total protein - albumin = 9.4 - 3.2 = 6.2 g/dL [62 g/L], so A/G = 3.2/6.2 = 0.52, a reversed ratio (normally above 1). A broad, diffuse gamma increase made by many clones of plasma cells is a polyclonal gammopathy, typical of chronic infection such as HIV, autoimmune disease and chronic liver disease. A monoclonal protein forms a narrow band and shows one heavy chain and only one light chain type on immunofixation. Diffuse staining with both kappa and lambda confirms that the increase is polyclonal.
- A: A broad band with diffuse staining in both light chain lanes is polyclonal.
- B: 1.94 is the ratio inverted (globulin divided by albumin).
- C: 0.34 is albumin divided by total protein, not by globulin.
Question 2 · Medium
An SPEP shows a normal albumin band but an almost flat alpha-1 band; all other fractions are normal. Deficiency of which protein is most likely?
1. AAlpha-1 antitrypsin
2. BTransferrin
3. CCeruloplasmin
4. DHaptoglobin
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Answer: A · Alpha-1 antitrypsin
Alpha-1 antitrypsin makes up about 90% of the alpha-1 band, so its deficiency leaves the band almost flat. Inherited deficiency causes early emphysema and liver disease. The next step is a quantitative alpha-1 antitrypsin level, followed by phenotyping or genotyping (for example PiZZ). A low alpha-1 band can also reflect heavy protein loss, but then albumin is low too.
- B: Transferrin is in the beta band.
- C: Ceruloplasmin is a minor alpha-2 protein.
- D: Haptoglobin is in the alpha-2 band.
Question 3 · Medium
SPEP results: total protein 4.5 g/dL [45 g/L]; albumin markedly decreased; alpha-1 normal; alpha-2 markedly increased; gamma decreased. Which condition fits best?
1. AMonoclonal gammopathy
2. BAlcoholic cirrhosis
3. CAcute inflammation
4. DNephrotic syndrome
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Answer: D · Nephrotic syndrome
In nephrotic syndrome, smaller proteins such as albumin and IgG are lost through the damaged glomeruli, so the albumin and gamma bands fall. The very large alpha-2 macroglobulin is held back and its level rises, so the alpha-2 band becomes prominent. Total protein falls while lipoproteins rise. Heavy proteinuria on urine testing confirms the picture.
- A: A monoclonal gammopathy shows a narrow spike, usually in the gamma region.
- B: Cirrhosis shows a broad gamma increase with beta-gamma bridging.
- C: Acute inflammation raises alpha-1 and alpha-2 but does not lower gamma or total protein this much.
Question 4 · Easy
After serum protein electrophoresis shows a possible monoclonal band, immunofixation is performed mainly to:
1. ACalculate the free light chain ratio
2. BMeasure its concentration in g/dL
3. CIdentify its heavy and light chain types
4. DMeasure total IgG, IgA and IgM levels
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Answer: C · Identify its heavy and light chain types
In immunofixation, the sample is separated in several lanes and each lane is overlaid with a different antiserum: anti-IgG, anti-IgA, anti-IgM, anti-kappa and anti-lambda. A monoclonal protein gives a sharp band in one heavy-chain lane and one light-chain lane at the same position, for example IgG kappa. It is also more sensitive than SPEP for small bands. The amount of M-protein is still measured from the SPEP scan.
- A: The free light chain ratio comes from a separate serum immunoassay.
- B: The M-protein concentration is measured by densitometry of the SPEP scan.
- D: Total immunoglobulin levels are measured by nephelometry and do not show clonality.
Question 5 · Easy
Serum protein electrophoresis is run by mistake on heparinized plasma. A sharp extra band appears between the beta and gamma zones. Which protein is it?
1. AFibrinogen
2. BTransferrin
3. CAlpha-1 antitrypsin
4. DHaptoglobin
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Answer: A · Fibrinogen
Plasma still contains fibrinogen, which migrates between the beta and gamma regions and forms a narrow band. The band can look like a small monoclonal protein. Repeating the test on serum makes it disappear, and immunofixation shows no matching immunoglobulin band. This is why protein electrophoresis is performed on serum.
- B: Transferrin is the main protein of the beta band and is present in serum too.
- C: Alpha-1 antitrypsin makes up most of the alpha-1 band.
- D: Haptoglobin migrates in the alpha-2 region.
Question 6 · Hard
On an SPEP scan, the gamma-region spike makes up 30% of the total area. Total protein is 8.0 g/dL [80 g/L] and albumin is 3.2 g/dL [32 g/L]. What is the M-protein concentration?
1. A1.0 g/dL [10 g/L]
2. B2.4 g/dL [24 g/L]
3. C1.4 g/dL [14 g/L]
4. D5.6 g/dL [56 g/L]
Answer and explanation in LearnFree account
Question 7 · Medium
In a patient with alcoholic cirrhosis, the beta and gamma bands merge on SPEP with no dip between them. This bridging is caused mainly by a rise in:
1. AIgE
2. BIgD
3. CIgA
4. DIgM
Answer and explanation in LearnFree account
Question 8 · Hard
Total protein is 7.8 g/dL [78 g/L] and albumin is 3.0 g/dL [30 g/L]. What is the albumin/globulin (A/G) ratio?
1. A0.4
2. B2.6
3. C1.6
4. D0.6
Answer and explanation in LearnFree account
Question 9 · Hard
Serum immunofixation shows a sharp band in the kappa lane, with no matching band in the IgG, IgA or IgM lanes. The most appropriate next step is:
1. AReport it as an IgG kappa M-protein
2. BRepeat the run using plasma
3. CReport a polyclonal kappa rise
4. DTest with anti-IgD and anti-IgE
Answer and explanation in LearnFree account
Question 10 · Easy
Routine serum protein electrophoresis is run in barbital buffer at pH 8.6. Most serum proteins move toward the anode at this pH because they are:
1. ACarried only by endosmosis
2. BPositively charged
3. CAt their isoelectric point
4. DNegatively charged
Answer and explanation in LearnFree account
Question 11 · Medium
Compared with the control lane, which condition best explains the patient's lane on this protein electrophoresis gel?
Figure: MedExams
1. ASystemic lupus erythematosus
2. BNephrotic syndrome
3. CMultiple myeloma
4. DAlpha-1 antitrypsin deficiency
Answer and explanation in LearnFree account
Question 12 · Hard
A serum with an M-spike is typed by capillary electrophoresis immunosubtraction. Each trace in the figure was run after the serum had been treated with the antiserum named beside it. How should the monoclonal protein be typed?
Figure: MedExams
1. AIgA lambda
2. BIgM lambda
3. CIgG lambda
4. DIgG kappa
Answer and explanation in LearnFree account
Question 13 · Medium
The serum protein electrophoresis trace shown compares a patient (solid, shaded) with a reference trace (dashed). The patient's pattern is best explained by:
Figure: MedExams
1. ANephrotic syndrome
2. BAcute inflammation
3. CCirrhosis of the liver
4. DMonoclonal gammopathy
Answer and explanation in LearnFree account
Question 14 · Easy
On the high-resolution serum protein electrophoresis trace shown, the peak marked X consists mainly of:
Figure: MedExams
1. AFibrinogen
2. BComplement C3
3. CHaptoglobin
4. DTransferrin
Answer and explanation in LearnFree account
Question 15 · Medium
Serum protein electrophoresis shows a narrow, dense band in the gamma region. What does this most suggest?
1. AA monoclonal gammopathy, such as myeloma
2. BAdvanced alcoholic cirrhosis
3. CNephrotic syndrome with protein loss
4. DAcute inflammation (acute phase response)
Answer and explanation in LearnFree account

Proteins: test procedures (electrophoresis, immunofixation)

An SPEP shows a normal albumin band but an almost flat alpha-1 band; all other fractions are normal. Deficiency of which protein is most likely?

SPEP results: total protein 4.5 g/dL [45 g/L]; albumin markedly decreased; alpha-1 normal; alpha-2 markedly increased; gamma decreased. Which condition fits best?

After serum protein electrophoresis shows a possible monoclonal band, immunofixation is performed mainly to:

Serum protein electrophoresis is run by mistake on heparinized plasma. A sharp extra band appears between the beta and gamma zones. Which protein is it?

On an SPEP scan, the gamma-region spike makes up 30% of the total area. Total protein is 8.0 g/dL [80 g/L] and albumin is 3.2 g/dL [32 g/L]. What is the M-protein concentration?

In a patient with alcoholic cirrhosis, the beta and gamma bands merge on SPEP with no dip between them. This bridging is caused mainly by a rise in:

Total protein is 7.8 g/dL [78 g/L] and albumin is 3.0 g/dL [30 g/L]. What is the albumin/globulin (A/G) ratio?

Serum immunofixation shows a sharp band in the kappa lane, with no matching band in the IgG, IgA or IgM lanes. The most appropriate next step is:

Routine serum protein electrophoresis is run in barbital buffer at pH 8.6. Most serum proteins move toward the anode at this pH because they are:

Compared with the control lane, which condition best explains the patient's lane on this protein electrophoresis gel?

A serum with an M-spike is typed by capillary electrophoresis immunosubtraction. Each trace in the figure was run after the serum had been treated with the antiserum named beside it. How should the monoclonal protein be typed?

The serum protein electrophoresis trace shown compares a patient (solid, shaded) with a reference trace (dashed). The patient's pattern is best explained by:

On the high-resolution serum protein electrophoresis trace shown, the peak marked X consists mainly of:

Serum protein electrophoresis shows a narrow, dense band in the gamma region. What does this most suggest?