Blood Sampling Without Needles: Addressing the Challenges of Traditional DBS

Blood microsampling is transforming the way healthcare providers, researchers, and patients think about blood collection.

Traditional dried blood spot (DBS) sampling methods, while revolutionary in their time, can be affected by variables such as hematocrit; the percentage of red blood cells in the blood, which may adversely impact test results.

New advances in fingerstick blood testing and microsampling devices offer alternatives that may minimize these challenges, improve patient comfort, and enhance accuracy.

How Fingerstick Blood Testing is Changing Healthcare

The COVID-19 pandemic accelerated the adoption of fingerstick methods for remote blood collection. This approach enables patients to draw their own blood at home, eliminating the need for clinic or lab visits.

A "fingerstick" is a minimally invasive procedure using a lancet to draw a drop or two of capillary blood from a finger. The specimen is then collected on microsampling device, once dried, the sample is mailed to a lab for analysis.

Fingerstick sampling is changing healthcare in several ways:

• Hospital and Clinic Care: Minimizes stress and pain associated with venous blood draws, which can be especially challenging in pediatrics, chronically ill patients, or those with needle anxiety.
• Telemedicine and Telehealth: Blood collection kits mailed to patients support remote monitoring and decentralized trials.
• Personal Health and Wellness: Empowers patients to manage their own health and participate in disease management from home.
• Public Health Studies: Facilitates large-scale population research by allowing at-home blood collection for serology and other studies.
  
  

Finger Prick Blood Draws: Are All Lancets Created Equal?

Fingerstick blood draws are generally quicker and more patient-friendly than venous draws. However, the choice of lancet and preparation technique can affect comfort and sample quality.

Lancet Types:

Standard: Exposed-blade lancets go deep into the skin and hit pain nerves, making repeated use painful and risky.

Safety Lancets: Spring-loaded blades that retract automatically, improving hygiene and reducing anxiety by keeping the blade hidden.

Vacuum Lancets: Penetrate more shallowly and use vacuum to draw blood, enabling sampling from non-fingertip sites.

Laser Lancets: Once popular but now largely discontinued due to higher pain and injury risk.

Preparations to Help Reduce Fingerstick Pain:

1. Wash hands with antibacterial soap rather than alcohol wipes to avoid drying and constriction.
2. Prick the side of the finger instead of the center for reduced sensitivity.
3. Select smaller-gauge or adjustable-depth lancets to fine-tune blood volume versus comfort.

These measures may help improve both the patient's experience and the quality of the sample collected.

The Evolution of Blood Sampling Technology

Blood sampling devices have an interesting history. Since 1947, scientists have been working to enhance the blood collection experience, starting with Vacutainer vacuum tubes and standardized blood collection tubes, and leading to dried blood spot (DBS) sampling.

This evolution has paved the way for today’s innovative technologies, such as Volumetric Absorptive Microsampling (VAMS™), which can help address issues like hematocrit variability.

For participants, traditional blood draws can be an uncomfortable experience, especially when they involve painful needles. Modern microsampling devices offer minimally invasive methods to collect blood without relying solely on venipuncture.

Addressing Hematocrit Challenges with Modern Microsampling

Hematocrit levels, which indicate the proportion of red blood cells in the blood, can significantly impact traditional dried blood spot (DBS) methods, leading to inconsistent results. Variations in hematocrit levels may change the distribution of analytes within a dried spot, complicating the interpretation of biomarkers.

Modern microsampling technologies, such as VAMS™, aim to address these hematocrit-related challenges by allowing for volumetrically precise collection that remains unaffected by changes in blood viscosity or cell concentration. This can provide:

• Volumetric Precision regardless of hematocrit levels.
• Reliable Analysis suitable for therapeutic drug monitoring or clinical diagnostics.
• Streamlined Workflows that reduce variability caused by user technique or environmental factors.
• Enhanced Stability allowing storage and transport of dried samples without refrigeration.

Microsampling: A Precise, Low-Volume Alternative

Microsampling technology allows for the collection of very small blood samples, typically less than or equal to 50 µL. This small volume is still sufficient to assess drug levels, biomarkers, and other clinical parameters. In fact, samples as little as 10–30 µL may be adequate for the analysis of blood, plasma, or serum exposures.

Mitra® microsampling devices provide a reliable and precise way to collect fixed volumes of blood, effectively eliminating the hematocrit-related bias often found in traditional dried blood spot (DBS) sampling. These devices are user-friendly and require minimal training, making them suitable for use in remote settings. Additionally, because dried blood samples do not need cold storage or special biohazard transportation, they help lower costs and simplify logistical processes.

Mitra® is particularly suitable for remote blood collection, featuring native barcoding and resealable bags for added convenience. With less pain and simpler logistics, these devices may improve patient satisfaction and study retention.

A New Era in Blood Collection

From overcoming patient discomfort to solving the hematocrit effect in traditional DBS, blood microsampling technologies like Mitra® with VAMS® represent a leap forward in clinical and research workflows. By enabling low-volume, high-quality sampling in decentralized settings, microsampling can help researchers, clinicians, and public health professionals improve participation, reduce costs, and maintain data quality, all without the logistical burden of traditional venipuncture.

As more real-world studies validate these methods, microsampling may become the new standard for blood collection in diverse fields, from clinical trials to population health.