A negative selection methodology using a microfluidic platform for the isolation and enumeration of circulating tumor cells

Abstract

Circulating tumor cells (CTCs) exist in the peripheral blood stream of metastatic cancer patients at rates of approximately 1 CTC per billion background cells. In order to capture and analyze this rare cell population, various techniques exist that range from antibody-based surface marker positive selection to methods that use physical properties of CTCs to negatively exclude background cells from a CTC population. However, methods to capture cells for functional downstream analyses are limited due to inaccessibility of the captured sample or labeling techniques that may be prohibitive to cell function. Here, we present a negative selection method that leverages a microfluidic cell concentrator (MCC) to allow collection and analysis of this rare cell population without needing cell adhesion or other labeling techniques to keep the cells within the chamber. Because the MCC is designed to allow collection and analysis of non-adherent cell populations, multiple staining steps can be applied in parallel to a given CTC population without losing any of the population. The ability of the MCC for patient sample processing of CTCs for enumeration was demonstrated with five patient samples, revealing an average of 0.31 CTCs per mL. The technique was compared to a previously published method – the ELISPOT – that showed similar CTC levels among the five patient samples tested. Because the MCC method does not use positive selection, the method can be applied across a variety of tumor types with no changes to the process.

Advancing the speed, sensitivity and accuracy of biomolecular detection using multi-length-scale engineering

“…Recently, several CTC capture systems have been reported that can use markers other than EpCAM for capture and/or analysis 93 , or that rely on negative selection so that a priori knowledge of the surface expression characteristics of CTCs is not required 94 . For example a microfluidic inertial focusing platform — the iCTC chip (Fig.…”

Cell Isolation and Recovery Using Hollow Glass Microspheres Coated with Nanolayered Films for Applications in Resource-Limited Settings

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 4 have demonstrated the ability to isolate high purity rare cells for clinical applications. [14][15][16][17][18][19][20][21][22][23][24] However, most of these approaches involve sophisticated microfabrication, excessive lab equipment, long process time and are labor intensive, which limit their practical usage in resource-limited settings.…”

Using circulating tumor cells to inform on prostate cancer biology and clinical utility

“…MagSweeper was reported to be able to gently extract live CTCs with high purity from unfixed, unfractionated blood 38,71 . The VerIFAST technique uses magnets to selectively and rapidly move the EpCAM positive cells bound to paramagnetic particles between immiscible liquids, where only the cells bound to immunomagnetic beads can cross between phases to enable rapid isolation of CTCs 48 . VerIFAST avoids the multiple transfer or wash steps required in many other CTC isolation methods, which can cause loss of rare cell populations.…”