Collecting biological data from large populations has historically depended on clinic-based blood draws, where trained professionals perform venipuncture under controlled conditions. While effective, blood collection performed in clinical settings generates barriers to participation and limits the geographic reach of population health and surveillance studies. Dried Blood Spot (DBS) kits offer a more flexible alternative to clinic-based blood collection, allowing participants to collect capillary blood through a simple fingerstick DBS test at home. As DBS samples are easy to dry, store and ship, DBS kits enable scalable monitoring of infectious diseases, metabolic health, and long-term biomarker trends. To support these applications, DBS kits must be carefully engineered to ensure accurate sampling, stable transport conditions, and seamless integration with laboratory workflows.
An important design consideration for DBS kits is accurate sample volume. Traditional DBS cards rely on blood spreading across filter paper, after which laboratories punch a fixed area from the dried spot for analysis. However, the distribution of blood on the substrate depends heavily on hematocrit levels, the proportion of red blood cells present in whole blood, which can introduce measurement variability in population health and surveillance studies. Samples with higher hematocrit are more viscous and spread less across the filter paper, whereas lower hematocrit allows blood to diffuse more widely. When DBS kits are deployed across large and diverse populations, this variability can influence the consistency of DBS test results. Substrate selection also affects DBS performance because different filter papers influence analyte stability, assay compatibility, and overall measurement consistency.
Addressing hematocrit-related variability often entails the use of volumetric sampling technologies in modern DBS kits, such as capillary-based volumetric discs. Rather than relying on the size of a blood spot on filter paper, these systems collect a predetermined microliter volume of blood during sampling. Obtaining this fixed level of blood through sampling standardizes the amount applied to the substrate, reducing inconsistency caused through differences in hematocrit and blood spreading in DBS testing conducted across large population health and surveillance studies.
After a DBS test is performed, the collected sample must travel from the participant’s home to the laboratory for analysis. Within this period, environmental conditions, particularly humidity and temperature, can influence analyte stability and overall sample integrity. Moisture is especially problematic because elevated humidity accelerates biological degradation and can compromise the reliability of DBS testing outcomes. These environmental factors are especially impactful in population health and surveillance studies, where DBS kits may be distributed across wide geographic regions and samples often travel long distances before reaching the laboratory. Maintaining appropriate humidity levels in transit is critical for reliable DBS testing. For many biomarkers measured in DBS samples, keeping humidity below 30% helps preserve analyte stability and protect sample integrity.
Addressing these challenges requires well-designed DBS kits that incorporate protective features that minimize environmental exposure throughout storage and shipping. They often include:
Together, such features allow DBS kits to support reliable DBS testing even when samples travel through diverse climates and shipping conditions as part of large population health and surveillance studies.
Because DBS kits are often used outside clinical environments, the collection interface must guide participants through a straightforward and reliable DBS test procedure. Clear, user-centered design is essential, as ease of use directly influences sample quality in population health and surveillance studies where participants perform collection independently. Lancet design plays a central role in successful blood sample collection. The lancet must generate sufficient capillary blood flow while remaining comfortable and simple to activate. Selecting the appropriate gauge and penetration depth helps participants produce an adequate sample without requiring specialized training. Visual guidance further improves the reliability of DBS tests performed at home. Many DBS kits incorporate printed indicators that show where blood should be applied and how large the sample should be, helping participants complete the procedure correctly. These design features reduce common collection errors, including:
In addition to supporting user-friendly collection, DBS kits must also enable safe sample return. Kits used in population health and surveillance studies typically follow UN3373 Category B shipping requirements for biological substances. Proper packaging ensures DBS samples can be safely transported through postal networks for laboratory analysis.
Large population health and surveillance studies frequently require laboratories to process thousands of DBS tests, placing strong demand on how DBS kits integrate with laboratory workflows. To support this scale, DBS cards are typically designed with standardized dimensions that allow robotic punch instruments to extract uniform sample discs for downstream analysis, enabling high-throughput processing. As DBS testing volumes increase, preserving traceability becomes equally important. A number of DBS kits consequently incorporate serialized two-dimensional barcodes that link each DBS test to participant records within laboratory information systems. Barcode-enabled tracking helps preserve a clear chain of custody from sample collection through to laboratory analysis. Reliable DBS testing at scale also depends on analytical compatibility. Aligning the chemistry of the filter paper substrate with the intended assay helps reduce background interference and supports consistent results across large population health and surveillance datasets.
RDA Spot develops DBS kits engineered for the demands of large population health and surveillance studies. Our DBS cards and kits support accurate sampling, stable transport, and seamless laboratory integration, enabling reliable decentralized DBS testing at scale. Designed for both participant usability and analytical consistency, RDA Spot DBS cards and sampling kits help researchers generate high-quality data across large surveillance programs. Speak with our specialists now to discover how our DBS cards and kits can improve data quality and enhance the efficiency of your next population surveillance study.