Tick testing (Lyme disease)

Tick testing is offered through the Napa-Solano-Yolo-Marin County Public Health Laboratory. The laboratory accepts ticks by mail for identification and testing. Testing a tick can provide information about the tick species and whether it carries pathogens, but testing a tick does not diagnose Lyme disease or other infections in a person.

People who found a tick on themselves, a family member, or a pet and want the tick identified and tested. Ticks are accepted by mail only; callers with questions can contact Marin County Public Health or the Public Health Laboratory for assistance.

What you need to know

• Tick testing is offered through the Public Health Laboratory.
• Testing a tick does not diagnose Lyme disease in a person.

Before you start

• Please review the tips for tick removal and collection.
• Write down when and where the tick was found.
• Place the tick in a small, sealed container or zip bag with a small piece of damp cotton or tissue.
• Ticks are accepted by mail only.

Tips for tick removal & collection

• Avoid touching the tick with your hands. If you must, use gloves or tissues as a barrier.
• If possible, have some else remove the tick using tweezers or forceps.
• Grasp the tick's mouthparts as close to the skin as possible and gently pull the tick straight out, steadily and firmly. Do not twist or jerk the tick.
• If mouthparts of the tick break off and remain in your skin, consult your physician.
• Place the tick into a clean capped container or zip plastic bag with a piece of paper towel or cotton moistened with tap water. (Note: do not use alcohol, formalin, or other liquids. Do not use tape. These materials can alter the ability to test for the Lyme organism.).
• Mail the tick as instructed below.

Tick testing by mail

1. Pay the tick testing fee online, or include a check as instructed on the payment portal. Tick identification costs $45. Fees may change.
2. Complete the tick requisition form and include the payment receipt number if you paid online. Requisition forms: Tick Requisition Form (English) and Tick Requisition Form (Spanish).
3. Mail your tick and form to: Napa-Solano-Yolo-Marin County Public Health Laboratory, ATTN: Tick Testing, 2201 Courage Drive, MS 9-200, Fairfield, CA 94533.

Effective immediately

• The Public Health Laboratory no longer tests the Dermacentor species ticks for the presence of Borrelia burgdorferi (the Lyme organism). Dermacentor variabilis, also known as the American dog tick, is one of the most common species found in California.
• Studies show that only the Ixodes species ticks can infect a host with B. burgdorferi upon blood-feeding. Ixodes pacificus, also known as the western blacklegged tick, is one of the most common species found in California. The Public Health Laboratory will continue testing the Ixodes species ticks for B. burgdorferi.
• The laboratory will still accept and identify the Dermacentor species ticks. The fee for identification and/or testing will remain the same ($45), regardless of the type of the tick submitted. No refunds will be issued.

Get help

• For lab questions, call the Public Health Laboratory at 707-784-4410 or visit the laboratory website.
• For other questions, call Marin County Public Health at 415-473-4163 or email Marin County Public Health.
• If you have symptoms or concerns, contact your healthcare provider. Tick testing does not replace medical care.