Abstract

Single Cell Analysis of Rare Cells

Thomas Kroneis, Head, Medical University of Graz

The analysis of rare cells longs to focus on two major issues, namely the enrichment for and the detection and confirmation of candidate rare cells allowing for reasonable downstream analysis. Current enrichment technologies mainly use sample pre-enrichment by means of density gradient centrifugation or red cell lysis, immunomagnetic depletion/enrichment strategies directed against surface marker, filtration by size or microfluidic devices as stand-alone procedure or in combination. Using our micromanipulation model of target cell spiking we contaminated peripheral blood with a defined number of cells and showed that filtration by size outperformed immunomagnetic approaches with respect to target cell recovery. Regarding the identification of rare cells we performed target cell population detection based on size (circulating fetal cells) size/morphology (circulating tumor cells) and XY-FISH (maternam microchimerism). Due to rare cell conditions in these experiments all applied marker for defining a candidate target cell population suffer from increased false positive rates. In this context we could show that rare cell analysis needs confirmation on the single cells level to descriminate false from true positive events - a pre-requisite for personalized rare cell analysis.