White blood cells play a central role in the bodyâs defence against bacterial, viral and fungal pathogens. In blood, there is only one white blood cell for every 1000 red blood cells, which makes their isolation a difficult task. Conventional isolation methods such as membrane filtration, differential centrifugation, or selective lysis of red blood cells could result in altered immune-phenotype or impaired viability of isolated WBCs and require a relatively large volume of blood.
In this project we have developed a microfluidic system with hydrodynamic cell traps that selectively capture white blood cells while not obstructing the flow path for red blood cells and platelets. The traps and therefore the immobilized cells are optically accessible, presenting an array of leukocytes that can be studied, at a sub-cellular level, with conventional biochemical labelling methods.
Whilst cell arrays are of general interest for cell population heterogeneity studies, e.g. different responses to external stimuli, our initial focus is on establishing nanoparticle association and uptake for different white blood cell types, identified by antibody labelling of distinct membrane receptors.