Development of an integrated fingerstick blood self-collection device for radiation countermeasures

Abstract

We report the development of system for packaging critical components of the traditional collection kit to make an integrated fingerstick blood collector for self-collecting blood samples of 100 μl or more for radiation countermeasures. A miniaturized vacuum tube system (VacuStor system) has been developed to facilitate liquid reagent storage, simple operation and reduced sample contamination. Vacuum shelf life of the VacuStor tube has been analyzed by the ideal gas law and gas permeation theory, and multiple ways to extend vacuum shelf life beyond one year have been demonstrated, including low temperature storage, Parylene barrier coating and container vacuum bag sealing. Self-collection was also demonstrated by healthy donors without any previous fingerstick collection experience. The collected blood samples showed similar behavior in terms of gene expression and cytogenetic biodosimetry assays comparing to the traditionally collected samples. The integrated collector may alleviate the sample collection bottleneck for radiation countermeasures following a large-scale nuclear event, and may be useful in other applications with its self-collection and liquid reagent sample preprocessing capabilities.

Fig 1. Design and prototyping of the integrated blood collector.

Exploded view of the integrated blood collector, where one lancet, two capillary-needle assemblies and two VacuStor tubes are integrated by 3D printed parts; the insert shows an integrated blood collector prototype.

Fig 2. Threshold vacuum testing setup.

(A) Image of a VacuStor tube and a capillary-needle assembly. The insert shows a 96-tube rack; (B) Schematics of VacuStor tube system before and immediately after transfer of all the blood.

Fig 3. Threshold vacuum theoretical prediction and experimental result.

Blue dots: experimental results of sample transfer percentage vs. VacuStor tube relative vacuum; red dashed line: relative threshold vacuum prediction by Eq (2).

Fig 4. VacuStor tube vacuum shelf life study.

(A) Change of normalized relative vacuum over time for VacuStor tubes under different conditions (Performance of one tube out of three replicates was plotted for each condition); (B) Means and standard deviations of nitrogen, oxygen leaking time constants for different Parylene coating thicknesses; the values for 5°C were also plotted for comparison. Three tubes were analyzed for each condition. Shelf lives were calculated using the mean values.

Fig 5. Packaging of VacuStor tubes inside a container by vacuum bag sealing.

(A) Schematics; (B) Theoretical glass VacuStor tube vacuum decay for different M and N values; (C) Experimental setup showing a 96-tube rack with a data logger being sealed within a vacuum bag and a plastic fixture to prevent data logger buttons being pressed by the vacuum bag after sealing; (D) logger data showing how the container pressure P_pk changed after sealing for 7 days.

Fig 6. Characterization of self-collected samples for gene expression and cytogenetic biodosimetry assays.

(A) Comparison of quantity (left) and quality (middle) of RNA isolated from blood using traditional method and the self-collector, the electropherogram (right) shows integrity of RNA by the self-collectors (RINs = 7.0–8.5, comparable to traditional method); (B) change of gene expression at 3 Gy relative to 0 Gy for real-time qRT-PCR (NS = not significant); (C) Micronuclei per binucleated cell for samples collected by traditional method or the integrated self-collector. The numbers are below 0.05 for all non-irradiated samples, and no significant difference between traditional and self-collector for the irradiated samples.