Tumor-derived circulating exosomes, enriched with a group of tumor antigens, have been recognized as a promising biomarker source for cancer diagnosis via less invasive procedure. Quantitatively pinpointing exosome tumor markers is appealing, yet challenging.
The sequential snapshots showing the release process of bead aggreagates after switching off the magnetic field during continuous flow in ExoSearch chip.
In this study, researchers have developed a simple microfluidic approach (ExoSearch) which provides enriched preparation of blood plasma exosomes for in-situ, multiplexed detection using immunomagnetic beads. The ExosSearch chip offers robust, continuous-flow design for quantitative isolation and release of blood plasma exosomes in a wide range of preparation volumes (10 uL to 10 mL). They employed the ExoSearch chip for blood-based diagnosis of ovarian cancer by multiplexed measurement of three exosomal tumor markers (CA-125, EpCAM, CD24) using a training set of ovarian cancer patient plasma, which showed significant diagnostic power (a.u.c. = 1.0, p = 0.001) and was comparable with standard Bradford assay. This work provides an essentially needed platform for utilization of exosomes in clinical cancer diagnosis, as well as fundamental exosome research.
CCD captured microscopic images of bead aggregates under negative and positive control experimental conditions. Image size is 200 µm x 200 µm.