The drug-checking strip market spent most of the last decade with no published standards governing what acceptable strip performance even meant. Manufacturers cited their own internal data. Buyers had no framework to evaluate the data against. The peer-reviewed literature documented case-by-case failure modes (false positives at high adulterant concentration, lot-to-lot variability, structural blind spots in analog detection, chiral sensitivity gaps) but a unifying community standard did not exist.
That changed in late 2025 and early 2026. Two interlocking standards now define the validation expectation for any rapid drug-checking strip serving the harm-reduction market. We aligned to both during product development and we test every production lot against the framework they describe. This page documents how.
The two community standards we operate against
AOAC SMPR® 2025.002 and SP 2025.001
In a collaboration funded by the U.S. National Institute of Standards and Technology (NIST), AOAC INTERNATIONAL convened a 52-person working group across academia, government, laboratory networks, harm-reduction nonprofits, and technology providers to develop the first formal performance standard for drug-checking lateral-flow immunoassays. The working group's output published in late 2025 and early 2026:
- AOAC SMPR® 2025.002 defines Standard Method Performance Requirements for the detection of benzodiazepines, fentanyl, medetomidine, nitazenes, and xylazine in selected drug product solids, liquids, and residues. It establishes minimum acceptable performance thresholds (sensitivity, specificity, robustness across matrices) that a strip must meet to be considered fit for purpose for harm-reduction drug checking.
- AOAC SP 2025.001 is the standard protocol for single-laboratory and independent-laboratory validation of strips against SMPR 2025.002.
The five analytes the standard explicitly covers are the five analytes DSG sells. We design and validate against the SMPR thresholds during product development, and we evaluate each production lot against the SP protocol before it ships.
The Notre Dame LQAS protocol
The community-published quality-assurance framework that preceded AOAC, and that AOAC's SP 2025.001 builds on, is the Lot Quality Assurance Sampling (LQAS) protocol developed at the Lieberman lab at the University of Notre Dame. Fernando et al. (2024) in Harm Reduction Journal formalized a two-phase test: a Fast Screen (10 strips at a defined positive concentration plus 10 strips against a blank) followed by an extended LQAS sample (15 additional strips, 25 total) when the Fast Screen passes. Lot rejection thresholds give 95 percent sensitivity at a 5 percent acceptable failure rate and 30 percent unacceptable failure rate.
The protocol pairs the lot screen with an interference panel of seven compounds (diphenhydramine, procaine, lidocaine, levamisole, methadone, methamphetamine, MDMA) tested at 2.0, 0.7, and 0.2 mg/mL. It is the most widely adopted lot-QA framework in the harm-reduction community, and it remains a useful daily-operations test in addition to the AOAC validation cycle.
What we run on every production lot
Each lot of a rapid drug-checking strip we ship has gone through, at minimum:
- Positive control screen. A defined number of strips tested at the analyte's published lower limit of detection in deionized water, a tap-water matrix, urine matrix where appropriate, and saline. Acceptance thresholds follow AOAC SP 2025.001 protocol where applicable, with the Notre Dame Fast Screen pass criteria as a minimum floor.
- Blank control screen. Equal number of strips tested against analyte-free matrices to verify no spontaneous positive lines.
- Interference panel. Cross-reactivity testing against the seven-compound panel from Fernando et al. (2024), extended with analyte-class-specific compounds (detomidine for medetomidine strips, caffeine for nitazene strips, designer-benzodiazepine analogs for benzodiazepine strips).
- Temperature stress check. Sample strips evaluated at low (refrigeration) and elevated (warm shipping) temperatures to characterize matrix robustness, since field conditions vary.
- Lot documentation. Lot identifier, expiration, and the QA results above are recorded and available to institutional buyers on request.
The data lives in our internal QA records. We make lot-specific summary data available to institutional buyers as part of the technical brief that accompanies a quote.
The independent academic literature we engage with
Beyond the formal community standards, our QA program is informed by the broader peer-reviewed work on lateral-flow strip performance that has accumulated over the last five years. The most influential body of work in this space comes from the Lieberman lab at the University of Notre Dame, where Marya Lieberman (Nancy Dee Professor of Cancer Research, awarded the 2025 American Chemical Society Gustavus John Esselen Award for Chemistry in the Public Interest) has led a series of comparative evaluations of harm-reduction test strips against authentic and adulterant-spiked samples. The papers most relevant to our QA framework include:
- Fernando H, Amate A, Hayes KL, Whitehead HD, Desnoyers C, Uzobuife E, Denchfield MS, Whitelatch B, Lieberman M. (2024). A lot testing protocol for quality assurance of fentanyl test strips for harm reduction applications. Harm Reduction Journal 21:152. doi:10.1186/s12954-024-01058-y
- Lieberman M, Badea A, Desnoyers C, Hayes K, Park JN. (2024). An urgent need for community lot testing of lateral-flow fentanyl test strips marketed for harm reduction in Northern America. Harm Reduction Journal 21:115. doi:10.1186/s12954-024-01025-7
- Hayes KL, Lieberman M. (2023). Assessment of two brands of fentanyl test strips with 251 synthetic opioids reveals "blind spots" in detection capabilities. Harm Reduction Journal 20:175. doi:10.1186/s12954-023-00911-w
- Amate A, Lieberman M. (2026). Chiral sensitivity of medetomidine lateral-flow immunoassay test strips. Harm Reduction Journal 23:19. doi:10.1186/s12954-025-01387-6
- Lockwood TLE, Vervoordt A, Lieberman M. (2021). High concentrations of illicit stimulants and cutting agents cause false positives on fentanyl test strips. Harm Reduction Journal 18:30. doi:10.1186/s12954-021-00478-4
Two additional research strands inform our specificity testing:
- Marland S, Nisbet LA, Nic Daéid N. (2025). Limitations of nitazene rapid test strips for harm reduction drug checking (caffeine interference). Harm Reduction Journal 22:5. doi:10.1186/s12954-025-01287-9
- de Vrieze J, Stove C, Vandeputte M. (2024). Detection of nitazene analogues with a commercially available lateral-flow assay. Harm Reduction Journal 21:118. doi:10.1186/s12954-024-01078-8
These are not our papers. They are the work of independent academic groups whose published methodology forms the technical bedrock of validated drug-checking strip evaluation. Our QA program is designed to be evaluated against this body of literature. We welcome that evaluation.
What this means for buyers
If you are a procurement officer at a state health department, a county harm-reduction program, an SDVOSB distributor, or an institutional buyer of any kind, three questions cleanly separate suppliers who have done the work from suppliers who have not.
- Does your strip meet AOAC SMPR® 2025.002 performance requirements for the analytes it claims to detect? Ask for the validation data. A serious supplier will provide it. AOAC SP 2025.001 defines the protocol the validation should follow.
- Do you run lot screening on every production lot before it ships? A serious supplier will describe the screen, the concentration, the number of strips, and the acceptable failure rate. Anything less is "we do internal QA" with no verifiable substance.
- Will you provide lot-level QA documentation with the order? Yes or no. The answer reveals the maturity of the supplier's QA program in one sentence.
We answer all three with yes, and we publish the standards we evaluate against because we want buyers to verify the answers themselves.
How to engage
Procurement officers, technical evaluators, and academic collaborators interested in our QA records or in independent evaluation of our products are welcome to contact us at Info@diagnosticsolutionsgroup.com. We provide lot-specific documentation, technical briefs, and validation summaries on request. We are also actively interested in being included in independent comparative evaluations conducted under AOAC SP 2025.001 or the Notre Dame LQAS protocol.
The literature is the bar. The bar is rising. We intend to keep clearing it.