Capillary blood microsampling,
more than a fingerstick.

Whole capillary blood, kept intact for the assays that don’t survive drying (drawn from the upper arm or fingertip at home, with handling and, where the assay requires it, controlled-temperature transport).

Talk to salesWhen liquid is needed →
Defined

What is liquid
capillary collection?

Liquid capillary blood microsampling collects a small volume of whole blood from the upper arm or fingertip and keeps it in liquid form (rather than drying it) so the sample reaches the laboratory intact. It is the family for assays that need the whole sample, and for downstream plasma separation. Because liquid blood is less stable than a dried sample, it travels stabilised and, where the assay requires, under controlled-temperature transport.

Where dried is the default, liquid is the managed exception (reserved for analytes that genuinely need an intact sample, and run through the same accredited-laboratory path under documented chain of custody).

Liquid whole blood, from the upper arm.
When liquid is needed

Liquid vs dried,
when each wins.

Most remote programmes are dried-first, because drying removes the cold chain. Liquid earns its place where the assay won’t tolerate drying, where a larger or whole sample is required, or where the workflow needs plasma. The assay decides (not preference).

Choose dried when…The analyte is stable dried and ships ambient (TDM, HbA1c, broad chemistry and screening). The cold-chain-free default.
Choose liquid when…The assay needs an intact sample, a larger volume, or plasma, and is validated on liquid capillary blood.
The trade-offLiquid preserves the whole sample but reintroduces handling and, often, controlled-temperature transport (a deliberate exception, not the rule).

Dried blood microsampling →

The devices

Drawn from the arm.

Liquid capillary devices draw whole blood from the upper arm or fingertip without a phlebotomist, a small applicator the patient activates at home. The makers describe the experience as far gentler than a venous draw.

YourBioAn upper-arm device that collects liquid capillary blood. YourBio describes the TAP draw as virtually painless.
At home, no clinicIt places collection in the patient’s hands (no appointment, no draw chair, no phlebotomist).

YourBio →

Comfort claims above are attributed to each device maker. Humans Nexus does not make an independent pain claim.

The cold-chain context

Handled, where the assay requires.

A liquid sample is less forgiving than a dried one, so logistics does more of the work. Where the analyte allows, chemical stabilisation (preservatives, buffers and internal standards) protects the sample in transit. Where it doesn’t, controlled-temperature transport is orchestrated and temperature-logged from collection to accessioning.

01Stabilise

Preservatives and buffers protect the analyte in transit (chemical stabilisation doing the work refrigeration otherwise would, where the assay allows).

02Controlled-temperature

For cold-chain-dependent analytes, controlled-temperature packaging is temperature-logged end to end and moved on medical courier networks.

03Documented custody

ID-matched, tamper-evident, every leg recorded, the audit trail that lets a liquid result be trusted for a medical decision.

Controlled-temperature transport is applied only where the assay requires it, never by default. See how we protect the sample →

Plasma separation

Plasma, without the centrifuge.

Many assays are validated on plasma, not whole blood, which traditionally means a centrifuge and a lab bench. At-home plasma separation is an emerging capability that separates plasma from a capillary sample at the point of collection, without a centrifuge, so a plasma-ready sample can be returned from home.

It is a developing area, and we treat it that way: deployed per assay, where the separation method is validated for the analyte and the laboratory has signed off on the workflow. Where it fits, it extends remote collection to plasma-based panels that liquid whole blood alone can’t serve, without sending the patient to a clinic.

□ Photo · Plasma separation
A centrifuge-free at-home plasma separation device in use, or a separated plasma sample ready for return. Clean, editorial, soft light.
Replace with asset
Who it’s for

Whoever runs the test.

LaboratoriesWhole-blood and plasma assays, collected remotely
Pharma & CRODecentralised trials needing intact samples
Digital healthGentle, lancet-free home blood in-app
InsurersWhole-blood biomarkers without a clinic visit

Infrastructure for healthcare and life sciences. Our partners reach the patient, and we never sell directly. Pharma & decentralised trials →

Good to know.

When do I need liquid rather than dried?

When the assay won’t tolerate drying, needs a larger or whole sample, or requires plasma, and is validated on liquid capillary blood. Dried is the default because it removes the cold chain; liquid is reserved for analytes that genuinely need an intact sample.

Is liquid capillary collection painful?

YourBio describes the TAP draw as far gentler than a venous needle, virtually painless. This is the maker’s claim; Humans Nexus does not make an independent pain claim.

Does liquid capillary blood need a cold chain?

Sometimes. Where the analyte allows, chemical stabilisation protects the sample at ambient temperature. Where it doesn’t, controlled-temperature transport is temperature-logged from collection to accessioning, applied only where the assay requires it.

Can plasma be collected at home?

At-home plasma separation is an emerging, centrifuge-free capability that separates plasma from a capillary sample at the point of collection. It is deployed per assay, where the method is validated for the analyte and the laboratory has approved the workflow.

Which devices collect liquid capillary blood?

YourBio draws whole capillary blood from the upper arm without a phlebotomist, used within validated kits run into ISO 15189-accredited laboratories under documented chain of custody.

The evidence

The research library.

12 papers

Sample type

Collection format

Device

Topic

Access

Fertility
Larger-volume capillary blood sampling is a valid alternative to assess progesterone and 17β-estradiol for cycle phase identificationSchlie et al. · Frontiers in Physiology · 2025 · Open accessCapillary samples of 100–250 µL taken alongside venous draws twice weekly across a full menstrual cycle agreed closely for progesterone and 17β-estradiol (concordance 0.911 and 0.919, minimal bias) (accurate enough to classify cycle phase and to flag anovulatory or luteal-phase-deficient cycles). The capillary blood was taken from the earlobe, so this validates the matrix and the volume rather than any one collection device.Open-access full text (PDF)
YourBio
Comparing capillary blood collection technologies: patient experience, device performance and clinical accuracyCollier et al. · Bioanalysis · 2025 · PaywalledA head-to-head of four upper-arm capillary devices (incl. TAP Micro Select) versus fingerstick and venous: experience and performance varied by device with none clearly superior, while analyte correlations with venous were similar across all.
Evaluation of a Simplified Upper-Arm Device for Vacuum-Assisted Collection of Capillary BloodSchaff et al. · Diagnostics · 2025 · Open accessA vacuum-assisted upper-arm device collected a mean 538 µL and met the volume target in 85.5% of cases; 17 of 19 analytes met CLIA agreement with venous, with pain lower than fingerstick.Open-access full text (PDF)
Comparison of capillary and venous plasma lipidomes: validation of self-collected blood for plasma lipidomicsHameed et al. · J. Lipid Research · 2025 · Open accessPlasma lipidomes from self-collected upper-arm capillary blood were statistically indistinguishable from paired venous plasma (most classes r=0.95–0.99) (validating at-home capillary self-collection for lipidomics).Open-access full text (PDF)
PediatricsYourBio
Transdermal blood sampling for C-peptide is a minimally invasive, reliable alternative to venous sampling in children and adults with type 1 diabetesBesser et al. · Diabetes Care · 2024 · Open accessIn 91 children and adults, capillary C-peptide taken with the TAP device matched venous sampling with 100% sensitivity and specificity for a clinically relevant level (≥200 pmol/L; r = 0.996). 63% preferred it to a needle against 7% who preferred the needle, and same-day bruising was 5.5% versus 34.8% after a venous draw.Open-access full text (PDF)
Feasibility, acceptability and safety of a device for self-collecting capillary blood in clinical trialsDasari et al. · PLOS ONE · 2024 · Open accessIn at-home and trial settings, a wet capillary device reliably collected a median ~450 µL with a 4.4% failure rate; 88% of adults preferred self-collection over venipuncture, with lower pain.Open-access full text (PDF)
YourBio
Maximizing microsampling: measurement of comprehensive metabolic and lipid panels using a novel capillary blood collection deviceCollier et al. · The Journal of Applied Laboratory Medicine · 2023 · PaywalledTAP II capillary serum (both professionally collected and self-collected) correlated with venous serum at R > 0.9 for eight analytes including ALT, AST, cholesterol, HDL and triglycerides. Creatinine correlated acceptably but carried a consistent negative bias, and carbon dioxide, potassium and albumin did not reach acceptable agreement: the useful reading is that the panel has to be validated, not the device alone.
Capillary blood stability and analytical accuracy of 12 analytes stored in MicrotainersFontaine & Saez · Practical Laboratory Medicine · 2023 · Open accessFingerstick blood self-collected into BD Microtainer tubes and posted at ambient temperature for 24 h agreed acceptably with paired serum for 11 of 12 analytes (HbA1c, lipids, creatinine, urea, urate, liver enzymes and total protein) with only AST falling outside limits.Open-access full text (PDF)
PediatricsYourBio
Durability of anti-spike antibodies in infants after maternal COVID-19 vaccination or natural infectionShook, Edlow et al. · JAMA · 2022 · Open accessThe paper records that the TAP II devices used for the infant draws were provided by YourBio Health, and that capillary serum was collected from babies as young as two months (the smallest patients sampled, without a heel prick or a venepuncture).Open-access full text (PDF)
YourBio
Remote self-collection of upper-arm capillary blood for autoantibody analysis in immune-mediated rheumatic diseasesZarbl et al. · RMD Open · 2022 · Open accessPatients self-collected upper-arm capillary blood with press-activated devices (incl. TAP II); autoantibody and CRP results agreed with venous (r≥0.98), were rated less painful, and 98.6% got enough blood within two attempts.Open-access full text (PDF)
Accuracy and tolerability of capillary self-sampling for inflammation and autoantibodies in rheumatoid arthritis: a randomized controlled trialKnitza et al. · Arthritis Research & Therapy · 2022 · Open accessCapillary self-sampling gave CRP and autoantibody values nearly identical to venous (ICC 0.97–0.998), was less painful, and the upper-arm route drew far higher acceptance and willingness to sample at home.Open-access full text (PDF)
YourBio
Quantitative metabolomics comparison of traditional blood draws and TAP capillary blood collectionCatala et al. · Metabolomics · 2018 · PaywalledMetabolomics of TAP capillary blood matched venous draws for most metabolites (amino acids, bile acids, acyl-carnitines r≥0.95); a small redox/energy subset differed with collection dynamics.

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).

Put liquid capillary on the platform.

Talk to us about remote whole-blood and plasma collection for your programme.

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