Effective March 4, 2026, an Antiphospholipid Antibody Panel will be available for adult patients in the emergency, observation, and inpatient settings across the Corewell Health System.
Corewell Health System, Emergency, Inpatient
Extreme Weather conditions adversely affect specimen integrity. Corewell Laboratory is committed to working with you to maintain specimen integrity during extreme conditions.
Exposing specimens to extreme temperatures can have a negative impact on patient results. We suggest that if the office pickup time is greater than one hour from the time the samples are being placed in the lockbox, you consider protecting the samples with some sort of insulated material.
Below are some steps to take in preparing specimens for lockbox pickup during extreme conditions.
• If the lockbox is not permanently affixed outside and is exposed to the elements, move it inside daily when arriving at the office in the morning. This will keep the lockbox temperature regulated and protected from extreme temperatures.
• For lockboxes permanently mounted outdoors and exposed to the elements, please keep specimens inside the office until either 15 minutes before scheduled pickup or leaving for the day.
• If it will not affect specimen integrity or patient care, please consider holding the specimen until the following day.
• Utilize draw centers (patient service centers) for specimen collection.
For questions regarding the best way to maintain the integrity of your samples and test information, please contact your Laboratory Sales Representative or laboratory customer services.
As part of our ongoing transition to Quest Diagnostics as our primary reference laboratory, an update has been made to the saliva collection device used for cortisol testing.
Quick Reference
Test: Cortisol, LC/MS, Saliva [Epic: LAB1232015, Interface: 1232015]
Approved Device: BLUE TOP Salivette® Cortisol Tube
Previously Accepted: White top tube
Status of White Top Tubes: No longer accepted – will be rejected
Action: Discard or return white top tubes and reorder blue top tubes via your supply form
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.
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.
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.
Effective December 3, 2025, meconium drug screen testing for Southeast Michigan will transition from ARUP to Corewell Health Reference Laboratory West.
This change ensures consistent, high-quality testing across all Corewell Health regions and clinically standardizes the services we provide as a system.
What’s Changing:
Southeast Michigan specimens will now be tested at Corewell Health Reference Laboratory West
Collection and transport processes remain unchanged.
Purpose of Test:
Meconium drug screen testing detects and documents fetal drug exposure during approximately the last trimester of a full-term pregnancy
For more information, please refer to the Lab Test Directory: Meconium Drug Testing LAB479
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.
Influenza prevalence fluctuates seasonally with the onset of “flu season” typically beginning its upswing in the month of December. It is important for providers to have an awareness of influenza prevalence (in addition to other respiratory viruses) to help guide when influenza testing should be pursued.