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Public Health Ontario > Home > Services & Tools > Laboratory Services > Measles - Diagnostic Serology
Measles - Diagnostic Serology
Specimen Type:

​Serum or plasma
Acute: Collect the acute sample within 7 days after the onset of the rash.
Convalescent: Collect the convalescent sample 7 to 10 days after the acute.


​Blood, clotted - vacutainer tubes (SST) 

Collection information:

​To order Collection Kits or other PHOL Supplies complete the Requisition for Containers and Supplies. The form should be faxed to Public Health Ontario Laboratory, Toronto at 416-235-5753 or your local PHOL.

Minimum volume required:

​5.0 ml whole blood or 1.0 ml serum or plasma


​Complete all fields of the General Test Requisition Form.  Please ensure the following fields are completed if diagnostic testing is requested:

• Symptoms
• Onset date


​Hemolysed, icteric, lipemic or microbially contaminated sera or plasma are not recommended for testing

Preparation prior to transport:

​Centrifuge if using SST. Place specimen in biohazard bag and seal. Specimens should be stored at 2-8°C following collection and shipped to PHOL on ice packs ASAP, where possible.

Special Instructions:

​Instructions for using SST tubes are found in the document titled: LAB-SD-008, Blood Collection Using Serum Separator Tubes.


​The Measles IgG and IgM tests are performed using ELISA (Enzyme Linked Immunosorbent Assay) test kits manufactured by Euroimmun (Germany). The IGG and IGM ELISA tests are both quantitative (IGG) and semi-quantitative (IGM) measuring human antibodies of the IgG and IgM classes against measles virus in serum or plasma. Test results are reported qualitatively together with a clinical interpretation based on the status of both IgG and IgM.

After a primary infection, both IgG and IgM antibodies develop within 3-7days after rash onset. Both antibodies then increase reaching a plateau 2-3 weeks later.
Antibody levels may be reported as Non-Reactive (no detectable antibody), Indeterminate (the level of antibody detected is considered borderline reactive or equivocal) or Reactive (antibody is detectable within the positive range of the assay).

Non-Reactive and Indeterminate levels of   both IgG and IgM antibodies may be observed in the acute stage of infection rising to reactive levels in subsequent weeks.
 In the absence of acute infection, indeterminate levels of IGG may represent very low levels of antibody many years after initial infection or vaccination whereas indeterminate levels of IGM may be due to declining levels of IGM several months post infection or possibly due to assay non-specificity.

If the acute blood sample shows low reactive, indeterminate or non reactive IgG and/or IgM results then a convalescent sample should be collected. Recent infection is confirmed if a significant rise in antibody levels is observed between acute and convalescent sera.
Please call the laboratory prior to sending specimens for STAT testing in order to ensure timely testing. STAT testing on the weekend requires authorization by the on-call medical microbiologist.
For more information on the interpretation of serological results refer to the document titled: LAB-SD-044, Diagnostic Interpretation of Viral Specific IgM and IgG Serology.


​When Measles infection is suspected - Contact your local Public Health Ontario Laboratory to ensure that appropriate testing is being requested and also contact your local Public Health Unit to inform them of all possible or suspect cases of measles.

For further information on Measles testing see the document titled: LAB-SD-079, Measles PCR-Addition to test Menu at PHO Laboratories. Or the clinical guideline document titled: Laboratory testing for Suspect Measles Cases.


​Measles Diagnostic IgM and IgG serology is performed daily Monday to Saturday.

The TAT for test results is up to 5 days. 

For an approved STAT request, results are usually available within 24 – 48 hours of receipt at the lab.


​Results are reported to the ordering physician or health care provider named on the requisition.

Specimens that are positive (reactive) for Measles IgM are also reported to the appropriate Medical Officer of Health as per Health Protection and Promotion Act.

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Page updated on [date/time] 23/05/2013 4:27 PM
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