Development of Microfluidic Instrumentation for
Application in the Diagnosis of Rare Anaemias

Abstract

Globally, the number of children born every year with a rare anaemia exceeds 500,000. The symptoms of rare anaemias range, depending on the mutation, from mild to severe, and in many cases prove to be fatal. The geographical prevalence of rare anaemias is concentrated in developing countries where resources available for diagnosis and treatment are scarce. The gold standard diagnosis of rare anaemia requires a three-tier investigation which is costly and not readily available in the areas most afflicted. As such, there is a need for a low-cost and user friendly method of diagnosis for these diseases.

This thesis investigates the diagnostic abilities of a bio-chemical assay that exposes red blood cells to a low pH shock using microfluidic techniques. This involved the development of a novel low-cost microfluidic instrument, which has been named MeCheM, to run Lab-on-a-Chip devices. The experimental techniques and protocols developed are critically reviewed using healthy blood samples as the control. The results from the control population establish baselines for comparison against the diseased samples. Subsequently, the developed methods are investigated for diagnostic capabilities using rare anaemia blood samples.

The results from these investigations suggest that there are observable differences for the developed Flow Test in the case of the Thalassaemia and Hereditary Spherocytosis disorders. Similarly, the developed Cell-Surface Adhesion measurements highlighted significant differences among the Sickle Cell samples. Additionally, secondary investigations indicated correlations between the gold standard Red Blood Cell Count and the RBC Count as measured using MeCheM, and Mean Corpuscular Volume and Average Cell Projected Area (pre-acid addition). The development of MeCheM, a novel microfluidic instrument, as a stand-alone device is a key output from this body of work.