Effective July 8, 2026, the Protein Electrophoresis, CSF and Serum will no longer be performed in-house. The new panel will now be sent to Quest Diagnostics.
Browsing Category
West Michigan
Effective July 8, 2026, serum viscosity tests ordered and collected at Corewell Health Southwest and West Michigan will be performed at the Corewell Health Reference Laboratory East.
This change includes an updated testing methodology, transitioning from an Ostwald capillary viscometer (water comparison) to a cone-plate viscometer. The reference range will also be updated from 1.4–1.8 units to 1.0–2.0 centipoise (cP).
A small positive bias is expected with the new method; however, this will not impact patient result trending.
TEST INFORMATION
Viscosity, Serum [LAB7650]
Effective March 4, 2026, Corewell Health Laboratories in West Michigan will discontinue performing testosterone testing (LAB173 and LAB2111222) and Corewell Health Southwest Michigan will discontinue Testosterone Free and Total testing (LAB173)
The following replacements will be available as a send out to Quest Diagnostics:
⇒Testosterone, Total, MS – Epic Code: LAB1232313
⇒Testosterone, Free, Bioavailable and Total, MS – Epic Code: LAB1232237
Corewell Health System, Southeast Michigan, Southwest Michigan, West Michigan
Update on Corewell Health and Quest Diagnostics Joint Venture
Dear Valued Client:
We are pleased to announce that Corewell Health and Quest Diagnostics, a leading national laboratory company, have completed the formation of their laboratory services joint venture (JV) named Diagnostic Lab of Michigan, LLC.
This multifaceted collaboration will broaden access to innovative, high-value laboratory services for you and other providers in Michigan. Excitingly, work has begun on a new state-of-the-art laboratory in Southfield, Michigan, to service the JV. This laboratory will not be operational until the beginning of 2027. We will provide updates on the laboratory start date as work progresses.
Improving Access to Diagnostic Innovation in Michigan Over Time
Corewell Health and Quest Diagnostics share the goal to broaden access to quality, accessible and affordable laboratory services for providers and patients in Michigan. We expect Diagnostic Lab of Michigan to concentrate the shared resources and expertise of Corewell Health and Quest Diagnostics on improving access to diagnostic innovation in Michigan.
Over time, Diagnostic Lab of Michigan will provide several new benefits, including:
• Greater convenience for patients, as Corewell Health and Quest Diagnostics combine their patient service networks to reach more patients in Michigan.
• Michigan-grown diagnostic innovation, including through automation in the new laboratory.
• Broad health plan access to support patient affordability.
Your current Corewell Health Lab Account Representative will continue supporting you as part of the new joint venture laboratory. If you have questions, please contact Matt Boring, Sales Director, 248-345-5604.
We appreciate your business and look forward to the continuation of high-quality laboratory services for our patients, providers and communities.
Sincerely,
Sarah Britton
Vice President, Laboratory Services
Corewell Health
General Information, Southwest Michigan, West Michigan
Outpatient Laboratory Hours of Operation Update
Effective January 1, 2026, the following outpatient laboratory (PSC’s) hours will be updated.
Corewell Health Big Rapids Hospital Laboratory
605 Oak St., Big Rapids, 49307
Monday to Friday: 6:30 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.
Corewell Health Gerber Hospital Laboratory – Newaygo
211 W. Pine Lake Drive, Newaygo, 49337
Monday to Thursday: 7 a.m. to noon.,12:30 p.m. to 3 p.m.; Friday: 7 a.m. to noon
Corewell Health Greenville Hospital Laboratory
615 S. Bower St., Greenville, 4883
Monday to Friday: 6:30 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.
Corewell Health Greenville Hospital Laboratory – Lakeview
8650 W Howard City-Edmore Road, Lakeview, 48850
Monday to Friday: 7 a.m. to 3:30 p.m.; Saturday: 8 a.m. to noon
Corewell Health Lakeland Hospitals Laboratory – Niles
31 N. St. Joseph Ave., Niles, 49120
Monday to Friday: 6:30 a.m. to 5 p.m.; Saturday: 7 a.m. to 11 a.m.
Corewell Health Pennock Hospital Laboratory
1009 W. Green St., Hastings, 49058
Monday to Friday: 6 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.
Corewell Health Pennock Hospital Laboratory – Lake Odessa
4294 Laurel Drive, Lake Odessa, 48849
Monday to Friday: 7 a.m. to 3 p.m.
Corewell Health Reed City Hospital Laboratory
300 N. Patterson Road, Reed City, 49677
Monday to Friday: 6:30 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.
Corewell Health Watervliet Hospital Laboratory
400 Medical Park Drive, Watervliet, 49098
Monday to Friday: 7 a.m. to 3:30 p.m.
Corewell Health Zeeland Hospital Laboratory
8333 Felch St., Zeeland, 49464
Monday to Friday: 6 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.
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.
Chemistry, West Michigan
Specimen Type Change for Outpatient Chemistry Tests – Effective December 3, 2025
Updated: 11/26/2025
Effective Date: December 3, 2025
What’s Changing?
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.
Why the Change?
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.
Key Points
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.
Resources
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.)
Questions?
Use the Contact Us link above.
General Information, West Michigan
Update: Laboratory Requisition Shipping Timeline – Please Plan Ahead
We want to share an important update regarding the shipping timeline for requisition orders.
As part of our ongoing efforts to streamline operations and improve service delivery, Corewell Health has transitioned to a new external printing vendor for requisition materials. While this change supports long-term efficiency, it does come with a temporary adjustment in turnaround time.
Requisition shipments will now take up to 12 business days to arrive, which is a longer timeframe than previously experienced.
To help ensure your office remains fully stocked and avoids any supply interruptions, we recommend placing orders at least three weeks in advance of running out of requisitions.
We appreciate your understanding and cooperation as we adapt to this new process. If you have any questions or need support with ordering, please don’t hesitate to reach out.
Thank you for your continued partnership!
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.
Referral/Sendouts, Southeast Michigan, Southwest Michigan, West Michigan
Primary Reference Lab Change to Quest Diagnostics
Effective November 19, 2025
Corewell Health Laboratory is transitioning to Quest Diagnostics as our primary reference testing laboratory. This change means that nearly all referral and send-out tests will now be performed by Quest Diagnostics. A limited number of tests will continue to be sent to other laboratories to ensure we meet the needs of our patients and clinicians.
What You Need to Know:
- Test Crosswalks: Tests currently performed at ARUP and Mayo Clinic Labs will be matched to comparable tests at Quest Diagnostics.
- Discontinued Tests: Tests with low utilization or those no longer deemed clinically necessary will be discontinued.
- New LAB Numbers: All tests will receive new LAB numbers, which must be updated in your EMR compendium if interfaced.
- Collection Devices: Some tests may require different collection devices.
- Transition Timeline:
- November 19, 2025: Focus on tests currently referred to ARUP.
- December 17, 2025: Focus on tests currently referred to Mayo Clinic Labs.
- Crosswalk Resources: Crosswalks between current and future test offerings will be provided to help you prepare.
- Test Directory Access: Please refer to your regional Lab Test Directory for details on specific test changes. ARUP and Mayo Clinic Lab test pages will include links to the corresponding Quest Diagnostic tests.
We understand the significance of these changes and are committed to supporting your practice throughout this transition. Updates and modifications will be communicated promptly.
Contact Information:
- Corewell Health East Sendouts: 248.551.9045
- Corewell Health West Referrals: 616.267.2753
- Or use the Contact Us link above.