Go-Live Date: December 17, 2025
Following Phase One in November, where tests previously referred to ARUP and some Mayo Clinic Lab tests were transitioned to Quest Diagnostics, we are now moving into Phase Two of this important change. Corewell Health Laboratory is continuing its transition to Quest Diagnostics as our primary reference testing partner.
All changes are for Corewell Health Laboratories in Southwest and West Michigan. For Laboratories in Southeast Michigan, please visit:corewellhealth.org/labcatalog and navigate to the Southeast Michigan site.
Updated: 11/26/2025
Effective Date: December 3, 2025
The preferred specimen type for most outpatient Chemistry tests will change from: Lithium Heparin Gel PST (mint green-top with gel) to Serum Separator SST (gold-top with gel)
Gray-top tube (Potassium Oxalate & Sodium Fluoride) will now be the preferred tube for glucose testing. Gold-top SST will remain acceptable for glucose testing and preferred for panels that contain glucose testing.
SST tubes provide improved specimen quality and stability, supporting more accurate test results.
Gray-top tubes contain additives that prevent glycolysis, ensuring more accurate glucose measurements.
Gold-top SST is now the preferred tube for outpatient Chemistry specimens.
Light green-top PST will still be accepted for the respective tests.
Gray-top is the preferred tube for glucose testing; gold-top is acceptable and should still be used for panels containing glucose.
Updated Preferred Tube Quick Guide
(Note: This change only impacts West Michigan; Southeast and Southwest Michigan sites already use gold-top SST tubes for many of these tests.)
Use the Contact Us link above.
The following information was updated in the Lab Catalog.
All changes are for Corewell Health Laboratories in Southwest and West Michigan. For Laboratories in Southeast Michigan, please visit:corewellhealth.org/labcatalog and navigate to the Southeast Michigan site.
The following information was updated in the Lab Catalog.
All changes are for Corewell Health Laboratories in Southwest and West Michigan. For Laboratories in Southeast Michigan, please visit: corewellhealth.org/labcatalog
If your patient is experiencing symptoms and requires a Covid test, please choose one of the options below:
Collect the specimen in your office and send the specimen to any Corewell Health Laboratory or with your Corewell Health Courier, if available.
• Please be sure to place a collected order in Epic or your EMR, or include a paper order with the specimen.
• Please make sure the specimen is labeled with 2 patient identifiers, date and time of collection, and source (nasopharyngeal or nares)
For all other options please visit: Corewell Health COVID-19 screening and testing
NOTE: Walk-in COVID-19 testing is not available at any of our sites, including emergency departments, urgent care locations or walk-in clinics. Testing is available to registered patients who are seeking medical treatment.
Effective Tuesday, February 20, 2024, the policy for home collected specimen drop offs for Outpatient Laboratories (“draw sites”) has been updated.
For all Corewell Health West Michigan locations: after registration, patients or their designated person will verify the specimen at the laboratory. Laboratory team members will verify the specimen is properly labeled and ensure they have everything needed to be able to test the specimen before the patient or their designated person leaves the building. This does not include specimens collected by a home health nurse or provider.
This will standardize our patient flow when arriving with a home collected specimen and will reduce the need for recollection due to missing information or improper collection.
When specimen collection orders are placed, please notify patients of the change to this process.
RELATED RESOURCES
Effective September 13, 2023, Corewell Health Laboratory will discontinue the Chlamydia Culture orderable. For patients 14 years of age and older, please order Chlamydia PCR.
• This specimen can be either a swab (genital, rectal, or throat) or a urine sample.
• The collection container is the STD-Multi-Collection Kit.
• For more information please visit: Chlamydia PCR
For patients that are under 14 years of age, a “Reference Miscellaneous Test” [LAB 848], must be ordered.
• This specimen can be either a swab (genital, rectal, or throat) or a urine sample.
• The collection container is the Aptima
• For more information please visit: APTIMA Chlamydia, NAAT, ThinPrep, Swab, Urine
As a reminder, PCR testing is also preferred for gonorrhea, when the specimen types are compatible.