Mikrofluidische Sensoren in der Durchflusszytometrie zur kombinierten optisch-elektrischen Analyse an Blutzellen
- Microfluidic sensors in flow cytometry for combined optical-electrical analysis of blood cells
Simon, Peter; Mokwa, Wilfried (Thesis advisor); Macdonald, R. (Thesis advisor)
Dissertation / PhD Thesis
Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2016
I developed microfluidic sensors for label-free flow cytometric cell differentiation by combined multiple AC electrical impedance and light scattering analysis. The measured signals are correlated to cell volume,membrane capacity and optical properties of single cells. For an improved signal to noise ratio, the microfluidicsensor incorporates two electrode pairs for differential impedance detection. One-dimensional sheath flow focusing was implemented, which allows single particle analysis at kHz count rates. Various monodisperse particles and differentiation of leukocytes in haemolysed samples served to benchmark themicrodevice applying combined AC impedance and side scatter analyses. In what follows, we demonstratet hat AC impedance measurements at selected frequencies allow label-free discrimination of platelets,erythrocytes, monocytes, granulocytes and lymphocytes in whole blood samples involving dilution only. Immunofluorescence staining was applied to validate the results of the label-free cell analysis. Reliable differentiation and enumeration of cells in whole blood by AC impedance detection have the potential to support medical diagnosis for patients with haemolysis resistant erythrocytes or abnormally sensitive leucocytes, i.e. for patients suffering from anaemia or leukaemia. Further, analysis of malaria-infected blood was accomplished. Differentiation and enumeration of infected red blood cells were achieved through various techniques. Label-free measurements, including AC electrical impedance and light scattering facilitate the possibility for true-false diagnosis. In addition, measurements including DNA staining enable a precise count of infected red blood cells allowing for monitoring of disease states.