Question 1

Where can I get a DNA test in Contra Costa County, California?

Accepted Answer

TestMark DNA operates 14 certified collection sites across 11 cities in Contra Costa County, with the largest concentration in Walnut Creek. No appointment is required and results are typically returned in 3 to 5 business days. Call (866) 702-7644 to confirm the closest site to you.

Question 2

Which cities in Contra Costa County have DNA testing available?

Accepted Answer

TestMark DNA serves 11 cities in Contra Costa County, California. The full list of cities and their collection sites is shown above on this page. Walnut Creek has the most collection sites and is typically the closest option for visitors traveling within the county.

Question 3

Do I need an appointment for DNA testing in Contra Costa County?

Accepted Answer

No appointment is required at most TestMark DNA collection sites in Contra Costa County. Walk-ins are welcome during regular business hours. Calling (866) 702-7644 before you arrive lets us confirm current wait times and which test is right for your situation.

Question 4

How long do DNA test results take in Contra Costa County, California?

Accepted Answer

Results for a standard DNA paternity test are typically returned within 3 to 5 business days from when all samples are received at the accredited laboratory. Turnaround applies to every collection site in Contra Costa County, regardless of which physical pickup location you visit.

Question 5

Are DNA test results from Contra Costa County admissible in court?

Accepted Answer

Results from a legal DNA test performed at an accredited TestMark DNA site with a completed chain-of-custody form are typically accepted in court, including in California courts. Personal (non-legal) tests are for private knowledge only and are not intended for legal use. Call (866) 702-7644 to confirm which test fits your situation.

Question 6

What types of DNA tests are available in Contra Costa County?

Accepted Answer

TestMark DNA collection sites in Contra Costa County support paternity, maternity, sibling, grandparent, avuncular, and immigration DNA testing, plus home DNA kit options. All tests are processed at accredited laboratories, the same facilities used by hospitals and physicians.

DNA Testing in Contra Costa County, California

DNA Testing Coverage in Contra Costa County

ZIP Codes Served in Contra Costa County

Largest Cities by Number of Sites

Cities in Contra Costa County

All Locations in Contra Costa County

1450 Treat Blvd

907 San Ramon Valley Blvd

4045 Lone Tree Way Ste B

2675 Pleasant Hill Rd

12677 Alcosta Blvd Suite 110

3466 Mt Diablo Blvd Ste C102

1914 Tice Valley Blvd

177 La Casa Via Suite 150

2400 Balfour Rd Ste 100

1505 St Alphonsus Way

2160 Appian Way Ste 205

2425 East St Ste 6

2540 East St D

140 Brookwood Rd Ste 102

Frequently Asked Questions