Home
HelpTest Code LAB438 Electrophoresis, Protein, 24 Hour, Urine
Useful For
Urine proteins can be grouped into 5 fractions by protein electrophoresis:
-Albumin
-Alpha-1
-Alpha-2
-Beta-globulin
-Gamma-globulin
The urine total protein concentration, the electrophoretic pattern, and the presence of a monoclonal immunoglobulin light chain may be characteristic of monoclonal gammopathies such as multiple myeloma, primary systemic amyloidosis, and light chain deposition disease.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Required
Supplies:
-Urine Container, 60 mL (T313)
-Aliquot Tube, 5 mL (T465)
Submission Container/Tube: Plastic, 60-mL urine bottle and plastic, 5-mL tube
Specimen Volume: 50 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Aliquot at least 25-mL specimen in plastic, 60-mL urine bottle and at least 1-mL of specimen in plastic, 5-mL tube.
3. Label specimens appropriately (60-mL bottle for protein electrophoresis and 5-mL tube for protein, total).
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.
Specimen Minimum Volume
25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 5 days | ||
| Ambient | 24 hours |
Refrigerate specimen during collection and send refrigerated.
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability
Day(s) Performed
Protein, total: Monday through Sunday
Electrophoresis, protein: Monday through Friday
Report available: 3 to 5 days
Method Name
PTU: Turbidimetry
PEU: Agarose Gel Electrophoresis
IFXU: Immunofixation
Urine proteins are separated in an electric field according to their size, shape, and electric charge (Helena Touch). The separation is performed on agarose gels. The proteins are visualized by staining with acid blue and the intensity of staining is quantitated by densitometry (Helena Quick Scan Touch). Multiplying by the urine protein concentration (Benzethonium Chloride) converts the percentage of protein in each fraction into urine concentration.(Instruction manual: Helena SPIFE Touch. Helena Laboratories, Corp; 11/2016; package insert: Helena SPIFE Touch SPE Pro 277. Helena Laboratories, Corp; 06/2018; Keren DF, Humphrey RL: Clinical indications and applications of serum and urine protein electrophoresis. In: Detrick BD, Hamilton RG, Schmitz JL eds. Manual of Molecular and Clinical Laboratory Immunology. 8th ed. 2016:chap 8)
CPT Code Information
84156
84166
86335-Immunofixation (if appropriate)
81050
Billing Code
3010196
30184167
30081050
30286336
Specimen Retention Time
See Individual Unit Codes
Interpretation
A characteristic monoclonal band (M-spike) is often found in the urine of patients with monoclonal gammopathies. The initial identification of an M-spike or an area of restricted migration should be followed by immunofixation to identify the immunoglobulin heavy chain and/or light chain.
Immunoglobulin heavy chain fragments as well as free light chains may be seen in the urine of patients with monoclonal gammopathies. The presence of a monoclonal light chain M-spike of greater than 1 g/24 hours is consistent with a diagnosis of multiple myeloma or macroglobulinemia.
The presence of a small amount of monoclonal light chain and proteinuria (total protein >3 g/24 hours) that is predominantly albumin is consistent with amyloidosis (AL) or light chain deposition disease (LCDD).
Because patients with AL and LCDD may have elevated urinary protein without an identifiable M-spike, urine protein electrophoresis is not considered an adequate screen for these disorders and immunofixation is also recommended.
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| EPU | Electrophoresis, Protein, 24 Hr, U | 81231-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 607970 | Albumin | 6941-9 |
| TP2 | Total Protein, 24 HR, U | 2889-4 |
| TM23 | Collection Duration | 13362-9 |
| 607971 | Alpha-1 globulin | 6794-2 |
| 607972 | Alpha-2 globulin | 6795-9 |
| VL21 | Urine Volume | 19153-6 |
| 607973 | Beta globulin | 94714-3 |
| 607974 | Gamma globulin | 94715-0 |
| 2833 | A/G Ratio | 44294-7 |
| 21446 | M spike | 42482-0 |
| 22307 | M spike | 42482-0 |
| 21447 | Impression | 32210-7 |
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| PTU | Protein, Total, 24 HR, U | Yes | Yes |
| PEU | Protein Electrophoresis, 24 Hr, U | No | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| IFXU | Immunofixation, 24 Hr, U | No | No |
Testing Algorithm
Urine protein electrophoresis alone is not considered an adequate screening for monoclonal gammopathies.
If a discrete electrophoresis band is identified, the laboratory will evaluate the urine protein electrophoresis and, if necessary, perform immunofixation at an additional charge.
Special Instructions
24-Hour volume is required.
Reference Values
PROTEIN, TOTAL
<229 mg/24 hours
Reference values have not been established for patients <18 years of age.
Reference value applies to 24-hour collection.
ELECTROPHORESIS, PROTEIN
The following fractions, if present, will be reported as mg/24 hours:
Albumin
Alpha-1-globulin
Alpha-2-globulin
Beta-globulin
Gamma-globulin