A low-cost, open-source centrifuge adaptor for separating large volume clinical blood samples

Abstract

Blood plasma separation is a prerequisite in numerous biomedical assays involving low abundance plasma-borne biomarkers and thus is the fundamental step before many bioanalytical steps. High-capacity refrigerated centrifuges, which have the advantage of handling large volumes of blood samples, are widely utilized, but they are bulky, non-transportable, and prohibitively expensive for low-resource settings, with prices starting at $1,500. On the other hand, there are low-cost commercial and open-source micro-centrifuges available, but they are incapable of handling typical clinical amounts of blood samples (2-10mL). There is currently no low-cost CE marked centrifuge that can process large volumes of clinical blood samples on the market. As a solution, we customised the rotor of a commercially available low-cost micro-centrifuge (~$125) using 3D printing to enable centrifugation of large clinical blood samples in resource poor-settings. Our custom adaptor ($15) can hold two 9 mL S-Monovette tubes and achieve the same separation performance (yield, cell count, hemolysis, albumin levels) as the control benchtop refrigerated centrifuge, and even outperformed the control in platelet separation by at least four times. This low-cost open-source centrifugation system capable of processing clinical blood tubes could be valuable to low-resource settings where centrifugation is required immediately after blood withdrawal for further testing.

An ultralow-cost portable centrifuge from discarded materials for medical applications

“…Sediment compactness after 5 min and 10 min of CentREUSE centrifugation was similar to that observed after centrifugation with a commercial device for 5 min at 10 RCF (0.31 mL ± 0.02 vs. 0.32 mL ± 0.03, p = 0.20) and 50 RCF (0.20 mL ± 0.02 vs. 0.19 mL ± 0.01, p = 0.15), respectively. Templates and instructions for construction of the CentREUSE are included as part of this open-source publication.Centrifugation is a crucial step in many diagnostic tests and therapeutic interventions [1][2][3][4] . However, achieving adequate centrifugation has historically required access to expensive, bulky, and electricity-dependent commercial devices, which are generally unavailable in resource-poor settings 2,4 .…”

“…The paperfuge has since been deployed in resource-poor settings for small-volume diagnostic applications (e.g., density-based separation of blood components in capillary tubes for detection of malaria parasites), thus demonstrating the real-world utility of an ultralow-cost, portable, human-powered centrifuge 2 . Since then, several other compact, low-cost, non-electric centrifugation devices have been described [4][5][6][7][8][9][10] . However, most of these solutions-much like the paperfuge-have been designed for use in diagnostic applications requiring sedimentation of relatively small volumes, and thus cannot be used for centrifugation of larger samples.…”

“…However, most of these solutions-much like the paperfuge-have been designed for use in diagnostic applications requiring sedimentation of relatively small volumes, and thus cannot be used for centrifugation of larger samples. Moreover, assembly of these solutions frequently requires access to specialized materials and tools that are often unavailable in underserved areas [4][5][6][7][8][9][10] .Herein, we describe the design, assembly, and experimental validation of a centrifuge constructed from commonly discarded materials, termed the CentREUSE, that builds on the paperfuge to allow for use in therapeutic applications-situations that commonly require sedimentation of larger volumes 1,3 . As proof of concept, we test the device by means of a real-world ophthalmic intervention: sedimentation of triamcinolone acetonide (TA) suspension for subsequent injection of pelleted drug into the vitreous of the eye.…”

“…Centrifugation is a crucial step in many diagnostic tests and therapeutic interventions [1][2][3][4] . However, achieving adequate centrifugation has historically required access to expensive, bulky, and electricity-dependent commercial devices, which are generally unavailable in resource-poor settings 2,4 .…”

“…However, most of these solutions-much like the paperfuge-have been designed for use in diagnostic applications requiring sedimentation of relatively small volumes, and thus cannot be used for centrifugation of larger samples. Moreover, assembly of these solutions frequently requires access to specialized materials and tools that are often unavailable in underserved areas [4][5][6][7][8][9][10] .…”