Volumetric absorptive microsampling: its use in COVID-19 research and testing.

COVID-19 led to changes in the way blood samples are collected. As societies were isolated to control viral spread, access to facilities became limited. Remote sample collection with a volumetric microsampling approach, using Mitra® devices based on VAMS® technology, proved to be highly effective. It allowed people to collect high-quality samples at home and post them to a laboratory. This enabled scientists to conduct large serosurveillance studies, with results showing that seroprevalence of COVID-19 was higher than initially expected. Furthermore, remote microsampling studies by several institutions were conducted to measure the relationship between antigen levels and antibody response and duration. VAMS technology was also used in COVID-19 clinical trials. In summary, the independent research reviewed in this paper proved that VAMS is an effective sample collection alternative.

Novel volumetric adsorptive microsampling technique for determination of perfluorinated compounds in blood.

Microsampling is an attractive option for significantly reducing the volume of blood taken for chemical analysis allowing for blood samples taken as a 'finger-prick' with a lancet. A novel, volumetric adsorptive microsampling (VAMS™) device, which reproducibly collects a small volume of 10 µL whole blood in a hematocrit-independent manner, is evaluated in a human biomonitoring setting, and has been utilized for analysis of several perfluoroalkyl acids (PFAA). The results show that the VAMS technique is applicable for PFAA analysis, method has good linearity, repeatability, accuracy and is sufficiently sensitive for samples from general populations. The stability of PFAAs with VAMS devices is shown to be acceptable, which supports the sampling and transportation strategy of several study designs. Furthermore, as well as allowing for a quick and efficient extraction and analysis flow path, the VAMS microsampler is an easy to use device in a real-world sample collection scenario.

A device for dried blood microsampling in quantitative bioanalysis: overcoming the issues associated blood hematocrit.

AIMS: A cross-laboratory experiment has been performed on a novel dried blood sampler in order to investigate whether it overcomes issues associated with blood volume and hematocrit (HCT) that are observed when taking a subpunch from dried blood spot samples. MATERIALS & METHODS: An average blood volume of 10.6 µl was absorbed by the samplers across the different HCTs investigated (20-65%). RESULTS: No notable change of volume absorbed was noted across the HCT range. Furthermore, the variation in blood sample volumes across six different laboratories was within acceptable limits. CONCLUSION: The novel volumetric absorptive microsampling device has the potential to deliver the advantages of dried blood spot sampling while overcoming some of the issues associated with the technology.

Fluorescent-conjugated polymer superquenching facilitates highly sensitive detection of proteases.

Sensor formats have been developed for detecting the activity of proteolytic enzymes based on fluorescent conjugated polymer superquenching. These sensors employ a reactive peptide sequence within a tether linking a quencher to a biotin. The peptide binds to sensors containing colocated biotin-binding protein and fluorescent polymer by means of biotin-biotin binding protein interactions, resulting in a strong quenching of polymer fluorescence. Enzyme-mediated cleavage of the peptide results in a reversal of the fluorescence quenching. These assays for protease activity are simple, sensitive, fast, and have the specificity required for screening chemical libraries for novel protease inhibitors in a high-throughput screening assay environment. These assays have been demonstrated for enterokinase, caspase-3/7, and beta-secretase.