On your lab requisition: Quest “Syphilis Antibody Cascading Reflex” (test code 90349)
The short answer
Syphilis Antibody Test, Reverse Sequence measures Treponema pallidum Antibody (Total), RPR with Titer (reflex, if reactive) and Second Treponemal Test (reflex, if discordant) from a standard blood draw. At TestWell it costs $49.99 plus a $6 lab processing fee, needs no fasting, and results post in 2–5 business days. Physician-authorized with no doctor's visit or insurance needed; draw at Quest.
TestWell Price
$49.99
+ $6 lab processing fee
This is the reverse-sequence syphilis algorithm, the approach many hospitals and laboratories now use for screening: the lab first runs a treponemal total-antibody immunoassay — antibodies to Treponema pallidum, which usually stay detectable for life after an infection. If that screen is reactive, the lab automatically reflexes to an RPR with titer, which indicates whether the infection is likely recent or active, and if the two results disagree, to a second, different treponemal test to settle it. Our standard Syphilis Test runs the traditional algorithm — an RPR screen first, with confirmatory testing if reactive — which is the right choice for most people who want a routine screen. Choose this reverse-sequence version if a clinician asked for a treponemal total antibody test or for Quest code 90349, if you have had treated syphilis in the past (the RPR can become non-reactive after treatment while treponemal antibodies persist), or if you want the algorithm that is more sensitive for very early and for late-stage infection. A reactive result needs follow-up with a clinician: because treponemal antibodies remain positive after successful treatment, the RPR titer and your history decide what it means. In New York and New Jersey, our standard Syphilis Test is already drawn at BioReference using its reverse algorithm.
Sample Type
Blood draw
Fasting
Not required
Results In
2–5 business days
Performed At
Quest
3 biomarkers tested
Your Syphilis Antibody Test, Reverse Sequence results will include values for each of the 3 biomarkers tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 2–5 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you. Already have results? Analyze them with your AI assistant against our physician-reviewed ranges.
No fasting required. Treponemal antibodies typically become detectable 3–6 weeks after exposure; a negative result soon after a possible exposure should be repeated.
TestWell orders the same Syphilis Antibody Test, Reverse Sequence the labs run for doctors' offices, so you can walk into Quest Diagnostics with our requisition — no doctor's visit, a licensed physician authorizes the order, and most patient service centers take walk-ins. The table shows each lab's own test code, the name printed on the requisition, what the lab charges on its own consumer site, and the price through TestWell at that lab (plus one $6 fee per order).
| Lab | Test code | On the requisition | Lab's own site | Through TestWell |
|---|---|---|---|---|
| Quest Diagnostics | test code 90349 | “Syphilis Antibody Cascading Reflex” | not sold direct | $49.99 + $6 |
You choose the lab at checkout; the requisition is written for that lab and arrives by email within minutes. New York and New Jersey orders draw at BioReference. Lab-direct prices are read from the labs' public pages and re-checked regularly.
Where to get it near you: patient service centers by state and city · search by ZIP code
A Reverse Sequence Syphilis Antibody Test costs $49.99 at TestWell — $55.99 all-in, since the $6 lab processing fee is charged once per order and there is no draw or physician fee. Hospital outpatient labs typically bill around $150.00 self-pay. With insurance you pay your plan's negotiated rate against your deductible; TestWell's price is fixed before the draw and HSA/FSA-eligible.
| Where you order | Price | One test, all-in | Notes |
|---|---|---|---|
| TestWell (drawn at Quest) | $49.99 | $55.99 | Includes the one $6 lab processing fee, charged once per order |
| Hospital outpatient lab, self-pay (typical) | $150.00 | $150.00 | Reference figure; hospital charges vary widely by facility and are often higher |
Lab test codes: Quest test code 90349. Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
Compare more: Quest Diagnostics price list · Labcorp price list · Quest vs Labcorp · Lab test price checker
Reverse Sequence Syphilis Antibody Test results are typically ready in 2–5 business days after your draw at Quest. TestWell emails you the moment they post, and your results dashboard shows each marker against its reference range with a plain-English explanation.
No, fasting is not required for a Reverse Sequence Syphilis Antibody Test — you can eat normally and book any time of day. Treponemal antibodies typically become detectable 3–6 weeks after exposure; a negative result soon after a possible exposure should be repeated.
Order the Reverse Sequence Syphilis Antibody Test online from TestWell for $49.99 (plus a $6 per-order lab processing fee) — no doctor's visit, referral or insurance needed. A licensed physician authorizes the order, then you walk into any Quest patient service center near you for the draw (the lab locator on our site lists the closest ones by ZIP code), and results arrive in 2–5 business days.
The CPT code for a Reverse Sequence Syphilis Antibody Test is 86780. You can order it from TestWell for $49.99 — no doctor's visit or insurance required, with results in 2–5 business days.
The Reverse Sequence Syphilis Antibody Test is Quest Diagnostics test code 90349 ("Syphilis Antibody Cascading Reflex") (CPT 86780). TestWell orders it under that code for $49.99 at Quest — no doctor's visit or insurance required, results in 2–5 business days. Codes verified against the labs' catalogs in 2026.
Medically reviewed by Youmna DiStefano, MD · Last reviewed October 2026
TestWell Price
$49.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
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Syphilis Antibody Test, Reverse Sequence
$49.99