Test Catalog

Test Id : SVISC

Viscosity, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detection of increased viscosity


Monitoring patients with hyperviscosity syndrome


This test is not useful for patients with small concentrations of monoclonal proteins.

Method Name
A short description of the method used to perform the test

Capillary Measurement

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Viscosity, S

Specimen Type
Describes the specimen type validated for testing

Serum Red

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube: Red top (serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 3 mL

Collection Instructions:

1. Keep specimen at 37 degrees C (eg, 37 degrees C Thermopak, heat block) until after centrifugation.

2. Centrifuge and aliquot serum into plastic vial.


If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Benign Hematology Test Request Form (T755)

-Hematopathology/Cytogenetics Test Request (T726)

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.75 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Red Refrigerated (preferred) 28 days
Frozen 28 days
Ambient 14 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detection of increased viscosity


Monitoring patients with hyperviscosity syndrome


This test is not useful for patients with small concentrations of monoclonal proteins.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Viscosity is the property of fluids to resist flow. Hyperviscosity may be manifested by nasal bleeding, blurred vision, headaches, dizziness, nystagmus, deafness, diplopia, ataxia, paresthesias, or congestive heart failure. Funduscopic examination reveals dilation of retinal veins and flame shaped retinal hemorrhages.


The most common cause of serum hyperviscosity is the presence of large concentrations of IgM monoclonal proteins, and Waldenstrom macroglobulinemia accounts for 80% to 90% of hyperviscosity cases. Hyperviscosity syndrome can also occur in multiple myeloma patients.


Because the ability of a monoclonal protein to cause hyperviscosity is affected by its concentration, molecular weight, and aggregation, sera with concentrations of monoclonal IgM greater than 4 g/dL, IgA greater than 5 g/dL, or IgG greater than 6 g/dL should be tested for hyperviscosity.


Serum viscosity and electrophoresis are recommended before and after plasmapheresis in order to correlate viscosity and M-spike with patient symptoms. This correlation may be useful for anticipating the need for repeat plasmapheresis.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

< or =1.5 centipoises

Provides information to assist in interpretation of the test results

Although viscosities greater than 1.5 centipoises (cP) are abnormal, hyperviscosity is rarely present unless the viscosity is greater than 3 cP.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Failure to follow specimen handling instructions may cause false-low results.


Hyperviscosity syndrome may not be present even if the viscosity is greater than 3 centipoises.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Gertz MA, Kyle RA: Hyperviscosity syndrome. J Intensive Care Med. 1995;10:128-141

2. Gertz MA: Acute hyperviscosity: syndromes and management. Blood. 2018;132(13):1379-1385

3. Kesmarky G, Kenyeres P, Rabai M, Toth K: Plasma viscosity: a forgotten variable. Clin Hemorheol Microcirc. 2008;39(1-4):243-246

4. Wood AW: Rheology of blood. In: Physiology, Biophysics, and Biomedical Engineering. CRC Press; 2012:217-233

Method Description
Describes how the test is performed and provides a method-specific reference

The Benson BV200 automated viscometer employs vacuum pressure through a capillary to measure the dynamic viscosity of serum samples. Samples at ambient temperature are aspirated by the sample probe, which is heated to 37 degrees C. Viscosity results are calculated by the instrument at both 25 degrees C and 37 degrees C temperature points. Viscosity units on board the instrument are mPa.s (milli-pascal seconds), which is the International Standard (SI) unit for viscosity. Centipoise (cP) units are named after French physicist Jean Leonard Marie Poiseuille and are used in the centimeter-gram-second (CGS) system of units. 1 mPa.s is equal to 1 cP.(Instruction manual: BV200 Automated Clinical Viscometer User Manual. Benson Viscometers; Ver. 1.5, 02/2020)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 4 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
SVISC Viscosity, S 3128-6
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
SVISC Viscosity, S 3128-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports

Test Update Resources

Change Type Effective Date
New Test 2021-08-10