Dried blood microsampling,
no cold chain.

Capillary blood that dries on a tip or a card and ships at ambient temperature (no cold chain, no ice, no excursion risk). There are three dried formats: VAMS, the dried blood spot, and quantitative DBS. We built the platform on the most accurate of them, VAMS.

Talk to salesThe three formats →
Our choice

We chose VAMS.

Every dried-blood format has to answer one question: how much blood is actually in the sample the laboratory analyses. A classic spot leaves it uncontrolled; VAMS fixes it at source. Volumetric absorptive microsampling wicks a fixed, known volume of capillary blood onto an absorbent tip (a set 10&ndash);30 µL regardless of how the blood would spread, and largely independent of haematocrit. The whole tip is then analysed, so there is no sub-sampling and no spot-area bias. That is precisely what quantitation needs, which is why VAMS is our default dried-blood solution on the platform.

Introduced by Denniff and Spooner in 2014, VAMS is now one of the most actively validated microsampling techniques in bioanalysis, with a decade of peer-reviewed method and clinical validation behind it. The evidence is aggregated below →

The device

Volumetric, by Neoteryx.

VAMS is delivered by the Neoteryx Mitra device: an absorbent polymer tip that fills from a fingertip drop in seconds, dries on its station, and ships at ambient temperature. The laboratory elutes the whole tip and runs the validated assay. Humans Nexus curates and supplies the device on the platform and assembles the regulated kit around it; Neoteryx is the manufacturer.

Therapeutic drug monitoringThe most mature clinical use (narrow-therapeutic-index drugs where a fixed, known volume is critical to the result).
Small molecules & metabolitesLC-MS/MS-ready dried extraction from a metered tip, transferred from venous methods.
Quantitative biomarkersValidated quantitative panels where volumetric precision materially improves accuracy.

Neoteryx Mitra →

The formats

Three ways to dry a sample.

All three dry the blood and ship it ambient. They differ in one thing (whether the volume analysed is controlled) and that difference decides which analytes each can quantify.

VAMSDried blood spotQuantitative DBS
PrincipleAbsorbent tip wicks a set volumeFree drops onto a cardMetered volume onto a card
Volume controlFixed at the tipUncontrolled, sub-punch of a free spotFixed by microfluidic metering
Haematocrit–area biasRemoved by designPresent on classic cardsRemoved at source
Analysed portionThe whole tipA punched sub-discThe whole metered disc
Best-established useQuantitative TDM, LC-MS/MSNewborn & population screening, serologyQuantitative work on a card
Ambient shippingYes, no cold chainYes, no cold chainYes, no cold chain

VAMS, the volumetric tip

The tip absorbs a fixed volume and is analysed whole, so the area-bias and homogeneity problems of a spot are removed by design. An honest nuance for method developers: removing the volumetric bias does not make every assay perfectly haematocrit-independent (a residual, haematocrit-dependent)recovery effect can persist for some analytes, so each assay is still validated per analyte rather than assumed. It is the format built for quantitation.

Dried blood spot, the proven classic

The dried blood spot is the original micro-volume format, and its pedigree is more than six decades deep: population newborn screening (tens of millions of infants a year) runs on it, and because immunoglobulins are stable when dried and serology reads a ratio rather than an absolute volume, DBS underpins large-scale antibody surveillance too. Its strengths are real. Its limitation is specific and narrow: getting an accurate concentration from a fixed sub-punch of a spot formed from an unknown volume, where the haematocrit effect, sub-punch variability and non-uniform analyte spreading all bear on the result. The card is excellent; the uncontrolled volume is the caveat.

Quantitative DBS (the spot, upgraded)

Quantitative DBS keeps everything patients and labs like about the card (finger-prick, dried paper, ambient post) and fixes the one weakness: it meters a precise, known volume onto the card and analyses the whole disc, so there is no sub-punch and no haematocrit-driven area bias. It is best understood not as a different sample type but as the dried blood spot done quantitatively: the classic card, with the volume brought under control.

The decision

Which format, when.

VAMSWhen volume is critical

Quantitation where a fixed, known volume decides the result (therapeutic drug monitoring, LC-MS/MS small molecules, quantitative biomarkers). Our default.

DBSWhen the assay reads a threshold

Ratio and threshold assays and validated screening at scale (newborn and population programmes, serosurveillance) where the classic card is proven and economical.

qDBSWhen you want the card, accurately

The card format kept, with volumetric metering added, for quantitative work that still wants a paper disc rather than a tip.

Whichever format fits, suitability is established per analyte through method validation before any patient-facing result (the format is chosen for the assay, not the other way round).

Validation

Validated before it reports.

Because dried formats can carry haematocrit and recovery considerations, every panel is validated per analyte along a research-to-clinical transfer pathway into ISO 15189-accredited laboratories, both analytical validation and clinical validation against a venous reference. Where a plasma-equivalent result is reported from capillary blood, an established, analyte-specific capillary-to-plasma relationship is applied, following international therapeutic-drug-monitoring guidance. VAMS (Neoteryx Mitra) is a CE-marked component within those validated kits.

The reference frameworks a laboratory implements against (the IATDMCT guidelines on dried-blood method validation and on capillary-to-plasma conversion) are listed in the reading below.

The evidence

The research library.

32 papers

Sample type

Collection format

Device

Topic

Access

Clinical Validation of Venetoclax Volumetric Microsampling in Leukemia, with Whole-Blood-to-Plasma Conversion and Self-Microsampling FeasibilityLevens et al. · Clinical Pharmacokinetics · 2026 · PaywalledIn AML and CLL, 91% of VAMS venetoclax results fell within ±20% of plasma once an individualised haematocrit correction was applied; among patients trying home collection, 18 of 21 sampled independently and 76% of returned samples were analysable (home self-microsampling proved feasible).
To Convert or Not to Convert? Official IATDMCT Guideline on Converting Capillary-Blood Microsampling Concentrations to Plasma ConcentrationsBoffel et al. · Therapeutic Drug Monitoring · 2026 · PaywalledGuidance on capillary-to-plasma conversion: method- and analyte-specific clinical validation with paired capillary–venous samples before reporting plasma-equivalent results.
Neoteryx Mitra
At-Home Self-Collection of Pharmacokinetic Data: Design and Results From a Phase 1 Open-Label Feasibility TrialRaoufinia et al. · Clinical Pharmacology in Drug Development · 2025 · Open accessA phase 1 trial designed around participant self-collection of pharmacokinetic samples at home, with video training and pre-assembled kits (evidence that the model is a training and logistics package, not only a device).Open-access full text (PDF)
Advancing Therapeutic Drug Monitoring for Oral Targeted Anticancer Drugs: From Hospital-Based Towards Home-SamplingMeertens et al. · Biomedical Chromatography · 2025 · Open accessA review of the transition from hospital-based to home sampling for oral targeted anticancer drug monitoring.Open-access full text (PDF)
Patient Centric Microsampling to Support Paxlovid Clinical Development: Bridging and ImplementationWan et al. · Clinical Pharmacology & Therapeutics · 2024 · PaywalledAt-home capillary microsampling carried pharmacokinetic sampling across the Paxlovid phase II/III programme, with fewer than 3% of more than 800 samples unusable, and the resulting data supported the Emergency Use Authorization and subsequent FDA approval (remotely collected samples accepted in a registrational filing).
Clinical validation of two volumetric absorptive microsampling devices to support home-based therapeutic drug monitoring of immunosuppressionLeino et al. · British Journal of Clinical Pharmacology · 2024 · PaywalledHead-to-head clinical validation of two VAMS devices for tacrolimus and mycophenolic acid, with roughly 86–88% of samples within ±20% of venous.
Using Dried Blood Spots to Quantitatively Detect Anti-SARS-CoV-2 IgG Antibodies by ELISA: A Validation StudyYlade et al. · American J. Tropical Medicine and Hygiene · 2024 · Open accessDBS achieved 100% sensitivity, 99% specificity and ~97% concordance versus paired serum (the strength of the classic card for ratio/threshold serology).Open-access full text (PDF)
PediatricsNeoteryx Mitra
Therapeutic Drug Monitoring of Tacrolimus Based on VAMS in Renal Transplant Pediatric Recipients — LC-MS/MS Method, Hematocrit Effect, and Clinical ApplicationKocur et al. · Pharmaceutics · 2023 · Open accessA validated VAMS LC-MS/MS tacrolimus method in pediatric kidney-transplant recipients correlated strongly with the reference method, with minimal haematocrit impact.Open-access full text (PDF)
Pediatrics
VAMS and parallel-reaction-monitoring mass spectrometry for tacrolimus trough measurements at home in paediatric heart-transplant patientsZhao et al. · J. Mass Spectrometry and Advances in the Clinical Lab · 2023 · Open accessAt-home VAMS tacrolimus sampling showed no significant difference from clinic venipuncture, with stability through postal shipping and strong family acceptance.Open-access full text (PDF)
Analytical and Clinical Validation of Assays for VAMS of Drugs in Different Blood Matrices: A Literature ReviewNugraha et al. · Molecules · 2023 · Open accessA structured review: many VAMS assays are analytically validated and can substitute for venous sampling for well-characterised analytes, though clinical-validation depth varies.Open-access full text (PDF)
Clinical validation and feasibility of VAMS for monitoring of nilotinib, cabozantinib, dabrafenib, trametinib and ruxolitinibZimmermann et al. · J. Pharmaceutical and Biomedical Analysis · 2023 · PaywalledVAMS matched serum for the kinase inhibitors nilotinib, cabozantinib, dabrafenib and ruxolitinib (r 0.94–0.97; serum reliably predictable for the first three), and 93% of at-home samples were collected correctly (at-home VAMS shown feasible for routine cancer-drug monitoring).
Pediatrics
VAMS and dried plasma spot for antifungal triazole agents (voriconazole, posaconazole, isavuconazole) in pediatric patients by LC-MS/MSSimeoli et al. · J. Pharmaceutical and Biomedical Analysis · 2023 · PaywalledIn children, VAMS and dried plasma spot voriconazole, posaconazole and isavuconazole correlated with fresh plasma (Spearman 0.82–0.94) and stayed stable at room temperature for at least 14 days (refrigeration-free antifungal TDM in paediatrics).
Neoteryx Mitra
Quantification of 25-hydroxyvitamin D2 and D3 in Mitra devices (VAMS) by UHPLC-HRMS for regular vitamin D status monitoringTuma et al. · J. Pharmaceutical and Biomedical Analysis · 2023 · PaywalledA UHPLC-HRMS assay quantified 25-hydroxyvitamin D2 and D3 from 20 µL Mitra VAMS samples with accuracy under 10% and precision under 11% (LOQ 5 ng/mL) (sensitive enough to flag deficiency and simple enough for untrained self-collection, enabling year-round vitamin-D monitoring).
VAMS-based blood capillary sampling for mass-spectrometry-based human metabolomics studiesVolani et al. · Metabolites · 2023 · Open accessCapillary VAMS blood covered more of the metabolome than plasma (capturing intracellular red-cell metabolites) and correlated moderately-to-well with venous (Spearman 0.66); the honest caveats are higher finger-prick replicate variability and a need for −80 °C storage within six hours.Open-access full text (PDF)
Therapeutic Drug Monitoring of Tyrosine Kinase Inhibitors Using Dried Blood MicrosamplesVerougstraete et al. · Frontiers in Oncology · 2022 · Open accessA review of dried blood microsampling for tyrosine kinase inhibitor monitoring, covering the analytical and clinical requirements for moving oral cancer-drug TDM out of hospital.Open-access full text (PDF)
A VAMS UPLC-MS/MS Method for Simultaneous Quantification of Tacrolimus, Mycophenolic Acid and Creatinine in Whole Blood of Renal Transplant RecipientsWang et al. · Pharmaceutics · 2022 · Open accessA single VAMS run quantified two immunosuppressants plus creatinine with minimal haematocrit effect (combined drug-and-organ-function monitoring from one dried tip).Open-access full text (PDF)
Neoteryx Mitra
Volumetric Absorptive Microsampling in Therapeutic Drug Monitoring of Immunosuppressive Drugs — From Sampling and Analytical Issues to Clinical ApplicationKocur & Pawiński · Int. J. Molecular Sciences · 2022 · Open accessA review positioning VAMS as state-of-the-art for immunosuppressant TDM: a fixed, accurate blood volume with a reduced haematocrit effect, home sampling and better adherence, especially in paediatric transplant (while flagging higher unit cost and a need for multicentre validation and cross-lab harmonisation before routine use).Open-access full text (PDF)
Pediatrics
Comparison of antibiotic sampling techniques: predicting plasma vancomycin from VAMS capillary versus venous/arterial whole bloodDownes et al. · Open Forum Infect. Dis. (IDWeek) · 2021 · Open accessThe honest counterpoint in children: VAMS predicted plasma vancomycin only modestly, venous/arterial VAMS was more accurate than capillary, and 29% of capillary samples were unusable for collection issues (collection technique and training matter as much as the assay).Open-access full text (PDF)
Neoteryx Mitra
Antibody-mediated immunity to SARS-CoV-2 and human coronaviruses: multiplex beads assay and VAMS to generate immune-repertoire cartographyWang et al. · Frontiers in Immunology · 2021 · Open accessFully remote, home-collected fingerstick VAMS (Mitra) samples from 54 participants measured IgG/IgA/IgM against spike and nucleocapsid across seven coronaviruses, cleanly separating pre-pandemic, convalescent and vaccinated groups (supporting VAMS for at-home serosurveillance).Open-access full text (PDF)
Neoteryx Mitra
Volumetric absorptive microsampling: its use in COVID-19 research and testingRudge · Bioanalysis · 2021 · Open accessA pandemic review of VAMS (Mitra): remotely self-collected home microsamples were shown to be as accurate as in-clinic samples for serology, keeping studies running when travelling to a clinic became risky.Open-access full text (PDF)
The evolving role of microsampling in therapeutic drug monitoring of monoclonal antibodies in inflammatory diseasesMingas et al. · Molecules · 2021 · Open accessA review of microsampling (VAMS and DBS) for TDM of therapeutic monoclonal antibodies (adalimumab, infliximab and others) in inflammatory disease: a convenient, home-friendly alternative to venepuncture that can preserve analytical accuracy, subject to assay-specific validation.Open-access full text (PDF)
Monitoring of Adalimumab Concentrations at Home in Patients with Inflammatory Bowel Disease Using Dried Blood SamplesBerends et al. · Therapeutic Drug Monitoring · 2020 · PaywalledAt-home dried blood sampling used for adalimumab concentration monitoring in inflammatory bowel disease (biologic TDM performed by the patient).
Opportunities and obstacles for microsampling techniques in bioanalysis: special focus on DBS and VAMSLondhe & Rajadhyaksha · J. Pharmaceutical and Biomedical Analysis · 2020 · PaywalledA review contrasting the formats (framing the haematocrit effect, non-uniform spreading and homogeneity limits of DBS as the problems volumetric sampling is designed to solve).
Dried blood samples can support monitoring of infliximab concentrations in patients with inflammatory bowel disease: A clinical validationBerends et al. · British Journal of Clinical Pharmacology · 2019 · Open accessA clinical validation showing dried blood samples can support infliximab concentration monitoring in inflammatory bowel disease.Open-access full text (PDF)
Analysis of the heterogeneous distribution of amiloride and propranolol in dried blood spot by UHPLC-FLD and MALDI-imagingUribe et al. · Molecules · 2019 · Open accessImaging shows analytes distribute non-uniformly within a single spot (one central, one peripheral) (so where a sub-punch is taken can change the answer).Open-access full text (PDF)
Official IATDMCT Guideline: Development and Validation of Dried Blood Spot-Based Methods for Therapeutic Drug MonitoringCapiau et al. · Therapeutic Drug Monitoring · 2019 · PaywalledThe consensus guideline defining the analytical- and clinical-validation requirements for dried-blood TDM (the standardisation reference for implementing a dried assay clinically).
Dried blood spots from finger prick facilitate therapeutic drug monitoring of adalimumab and anti-adalimumab in patients with inflammatory rheumatic diseasesKneepkens et al. · British Journal of Clinical Pharmacology · 2017 · PaywalledFinger-prick dried blood spots supported monitoring of both adalimumab and anti-adalimumab antibodies in inflammatory rheumatic disease (biologic TDM without a venous draw).
Clinical feasibility of dried blood spots: analytics, validation, and applicationsEnderle, Foerster & Burhenne · J. Pharmaceutical and Biomedical Analysis · 2016 · PaywalledA review of clinical DBS across TDM, metabolic monitoring and trials, arguing that analytical and clinical validation must be obligatory before clinical use.
Does volumetric absorptive microsampling eliminate the hematocrit bias for caffeine and paraxanthine in dried blood samples? A comparative studyDe Kesel, Lambert & Stove · Analytica Chimica Acta · 2015 · PaywalledVAMS eliminated the variable haematocrit bias seen with DBS, but a residual haematocrit-dependent recovery effect persisted at high haematocrit (the nuance that assays still need per-analyte validation).
New microfluidic-based sampling procedure for overcoming the hematocrit problem associated with dried blood spot analysisLeuthold et al. · Analytical Chemistry · 2015 · PaywalledThe foundational quantitative-DBS work: a microfluidic layer meters a controlled 5–10 µL onto a standard card in seconds, targeting the haematocrit problem at source.
Neoteryx Mitra
Volumetric Absorptive Microsampling: A Dried Sample Collection Technique for Quantitative BioanalysisDenniff & Spooner · Analytical Chemistry · 2014 · PaywalledThe foundational VAMS paper: a fixed ~10 µL is absorbed with under 5% volume variation across a 20–70% haematocrit range, overcoming the area bias and homogeneity problems of the dried blood spot.
Hemato-critical issues in quantitative analysis of dried blood spots: challenges and solutionsDe Kesel et al. · Bioanalysis · 2013 · PaywalledThe canonical review of the haematocrit effect (decomposing it into recovery bias, matrix effects, spot-size/homogeneity variation and analyte-distribution bias).

External links open an open-access full text where one exists, otherwise the publisher or PubMed record. These citations describe the published evidence for the collection formats and devices (not claims about specific Humans Nexus assays, which are validated per analyte and per laboratory).

Who it’s for

Whoever runs the test.

LaboratoriesAdd a dried-blood format, quantitative or screening
Pharma & CRODecentralised trials, TDM and serosurveillance
Public healthNewborn and population screening at scale
Digital healthPrecise, cold-chain-free home blood in-app

Infrastructure for healthcare and life sciences. Our partners reach the patient, and we never sell directly.

Good to know.

How is VAMS different from a dried blood spot?

VAMS absorbs a fixed, known volume on a tip and is analysed whole, removing the spot-volume and homogeneity variability that limit quantitation from a classic dried blood spot. Quantitative DBS reaches the same goal on a card by metering a fixed volume onto it. The dried blood spot itself remains excellent for threshold assays such as serology.

Does VAMS remove the haematocrit effect entirely?

It removes the volumetric/area bias by design, but not automatically every haematocrit influence (a residual, analyte-dependent recovery effect can remain). That is why each assay is validated per analyte rather than assumed to be haematocrit-independent.

Is the dried blood spot less accurate?

Not in general. DBS is proven and excellent for ratio and threshold assays (newborn screening and serology run on it) and for many validated drugs. Its limitation is specific: absolute quantitation from a fixed sub-punch of a spot made from an uncontrolled volume. Where that matters, VAMS or quantitative DBS is the better choice.

Do dried formats need a cold chain?

No. Once dry, the VAMS tip and the DBS card are stable at ambient temperature and ship by standard tracked return (no refrigeration, no temperature logging). This is why dried is the default for remote blood collection.

Can a home capillary result substitute for a venous draw?

For well-characterised analytes, yes (clinical-validation studies report good agreement with venous blood, and where a plasma-equivalent result is needed an established capillary-to-plasma relationship is applied). It is established per analyte, following international TDM guidance, before any patient-facing reporting.

Are the devices regulated?

Neoteryx Mitra (VAMS) is a CE-marked component within validated kits, with method validation in ISO 15189-accredited laboratories before patient-facing reporting. Device-level regulatory status is held by the manufacturer; Humans Nexus assembles the regulated kit around it.

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