Microsampling tools for collecting, processing, and storing blood at the point‐of‐care

Abstract

In the wake of the COVID-19 global pandemic, self-administered microsampling tools have reemerged as an effective means to maintain routine healthcare assessments without inundating hospitals or clinics. Finger-stick collection of blood is easily performed at home, in the workplace, or at the point-of-care, obviating the need for a trained phlebotomist. While the initial collection of blood is facile, the diagnostic or clinical utility of the sample is dependent on how the sample is processed and stored prior to transport to an analytical laboratory. The past decade has seen incredible innovation for the development of new materials and technologies to collect low-volume samples of blood with excellent precision that operate independently of the hematocrit effect. The final application of that blood (i.e., the test to be performed) ultimately dictates the collection and storage approach as certain materials or chemical reagents can render a sample diagnostically useless. Consequently, there is not a single microsampling tool that is capable of addressing every clinical need at this time. In this review, we highlight technologies designed for patient-centric microsampling blood at the point-of-care and discuss their utility for quantitative sampling as a function of collection material and technique. In addition to surveying methods for collecting and storing whole blood, we emphasize the need for direct separation of the cellular and liquid components of blood to produce cell-free plasma to expand clinical utility. Integrating advanced functionality while maintaining simple user operation presents a viable means of revolutionizing self-administered microsampling, establishing new avenues for innovation in materials science, and expanding access to healthcare.

Advancing Global Health Surveillance of Mycotoxin Exposures using Minimally Invasive Sampling Techniques: A State-of-the-Science Review

“…Overall, the development of field-friendly sampling methods , will facilitate longitudinal cohort studies investigating mycotoxins and associated health risks, for which there are currently very few studies . Due to its low cost and convenience, DBS sampling is well-suited for extending temporal biomonitoring and surveillance studies in low-resource settings, where mycotoxin exposures and associated health risks are the most prevalent .…”

“…An important limitation of minimally invasive sampling approaches is the analytical challenges associated with small sample volumes, which limit the ability to analyze samples for additional biomarkers. This limitation may be overcome by continued innovations in microsampling methods and continued improvements in analytical sensitivity and precision of mass spectrometry instrumentation , as well as multimycotoxin assays. , Advancing the science of DBS/DSS sampling and VTS for measuring exposure to mycotoxins and implementing these approaches widely as public health tools should be a research priority to promote global health equity. Additional work is needed to identify appropriate and sustainable financing mechanisms and implementation strategies to incorporate DBS/DSS sampling and VTS into global health surveillance systems for monitoring population-level exposures to mycotoxins in regions where exposures are endemic and in regions where exposures are expected to increase with global climate change. ,, …”

Hematocrit-Independent Sampling Enables White Blood Cell Counts from Patterned Dried Blood Spot Cards

“…Dried blood spot (DBS) cards, such as the Whatman 903 Protein Saver card, offer a simple method for sample collection, storage, and transportation away to centralized facilities for downstream analyte detection and/or quantification. − To date, DBS cards have been used to measure markers for a diverse range of medical applications including general health, disease diagnostics and monitoring, newborn screening, drug monitoring, and fertility health. − While DBS cards are well suited for sampling fingerstick samples of whole blood in limited-resource or at-home settings, extraction of intact WBCs, which would be required for use with a hematology analyzer, is challenging due to the dehydration of the sample (i.e., altering cell size or granularity) and subsequent cellular hemolysis (i.e., loss of cells). Consequently, there have been few successful published reports on quantifying WBCs directly from DBS cards.…”

Capillary blood stability and analytical accuracy of 12 analytes stored in Microtainers®

“…While most diseases remain silent during their subclinical phase, the biochemistry of human blood is typically altered providing early signals of an evolving pathology. Changes are usually detected by common laboratory tests using blood specimens obtained by a medical technician [ 1 ]. However, this practice represents a logistic barrier for disease screening purposes.…”