Specimen Collection
10 mL Collect 24hr Urine (Preferred)
Turnaround Time: Within 3 days
Diagnostic Use and Interpretation

Quantitation of monoclonal bands in urine (Bence-Jones protein) is done by densitometry of the electrophoresis gel.

The band quantitation is expressed in mg/mmol creatinine (random and 24h urine samples) and in g/24h (only for 24h collects).

The uncertaintly of measurement is of the order of 20%.

Contact Information

Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.

If the query concerns a specific patient please include the NHI number in your email.

If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).

Individual chemical pathologists may be contacted but will not be available at all times.

After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.

Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402

Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052

Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427

Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427

Dr Sakunthala Jayasinghe: Sakunthala@adhb.govt.nz ext. 23427

Specimen Collection

Plasma is not suitable for electrophoresis as fibrinogen may mask a paraprotein band.

5 mL SST Serum (Preferred)

5 mL Plain Blood

200 uL Microsample Serum

.

Reference Intervals

Uncertainty of Measurement:

For the gamma region : The uncertainty of the quantitation of paraproteins (if present) is 10% at a concentration of 20 g/L, and 20% at a concentration of 8 g/L

For the non-gamma region : The uncertainty of the quantitation of paraproteins (if present) is 5% at a concentration of 24 g/L.

Turnaround Time: Within 3 days

Test performed on weekdays.

Diagnostic Use and Interpretation

Band quantitations are performed by densitometry. This will be done automatically every time a monoclonal band is seen on electrophoresis.

This is the preferred method for monitoring MGUS and myeloma.

Faint bands in the gamma region (less than 1 g/L) cannot be accurately quantitated.

Paraproteins in the non-gamma region are measured down to 3 g/L

In patients with cryoglobulins, band quantitations may give highly variable results, due to variable loss of the protein by precipitation during sample transport and processing. In such cases the sample has to be processed with rigorous attention to maintaining the temperature at 37C; contact the duty Chemical pathologist for advice.

Measurement of immunoglobulin levels by immunoassay (e.g. IgG, IgA or IgM levels) may be inaccurate because:

(a) they include ALL immunoglobulins of that class, not only the paraprotein

(b) some paraproteins react anomalously in immunoassays, giving falsely high or low results.

Last updated at 15:26:00 06/01/2025