A portable centrifugal analyser for liver function screening

Charles E. Nwankire, Monika Czugala, Robert Burger, Kevin J. Fraser, Tríona M. O׳Connell, Thomas Glennon, Blessing E. Onwuliri, Isikaku E. Nduaguibe, Dermot Diamond, Jens Ducrée

Mortality rates of up to 50% have been reported after liver failure due to drug-induced hepatotoxicity and certain viral infections (Gao et al., 2008). These adverse conditions frequently affect HIV and tuberculosis patients on regular medication in resource-poor settings. Here, we report full integration of sample preparation with the read-out of a 5-parameter liver assay panel (LAP) on a portable, easy-to-use, fast and cost-efficient centrifugal microfluidic analysis system (CMAS). Our unique, dissolvable-film based centrifugo-pneumatic valving was employed to provide sample-to-answer fashion automation for plasma extraction (from finger-prick of blood), metering and aliquoting into separate reaction chambers for parallelized colorimetric quantification during rotation. The entire LAP completes in less than 20 min while using only a tenth the reagent volumes when compared with standard hospital laboratory tests. Accuracy of in-situ liver function screening was validated by 96 separate tests with an average coefficient of variance (CV) of 7.9% compared to benchtop and hospital lab tests. Unpaired two sample statistical t-tests were used to compare the means of CMAS and benchtop reader, on one hand; and CMAS and hospital tests on the other. The results demonstrate no statistical difference between the respective means with 94% and 92% certainty of equivalence, respectively. The portable platform thus saves significant time, labour and costs compared to established technologies, and therefore complies with typical restrictions on lab infrastructure, maintenance, operator skill and costs prevalent in many field clinics of the developing world. It has been successfully deployed to a centralised lab in Nigeria.