Microfluidic probe

Overview

Microfluidics are generally closed systems inside which samples must pass and to which user-to-chip interfaces must be established. We have developed a microfluidic probe (MFP) that overcomes the usual limitations of microfluidics by combining the concepts of microfluidics and of scanning probes.

With this approach, liquid boundaries formed by hydrodynamic forces underneath the MFP confine a flow of processing solution and replace the solid walls of closed microchannels, Figure 1. The MFP is therefore mobile and can be used to process large surfaces and objects by scanning across them. MFPs are versatile as they can microarray proteins on surfaces (Fig. 2a), form chemical gradients on surfaces (Fig. 2b), effect multiphase laminar flow patterning (Fig. 2c), "erase" patterns from a surface (Fig. 2d), localize staining of adherent cells, and address single living cells on a surface (Fig. 2e). Three videos show, respectively, the confined flow between two apertures of an MFP, an MFP microarraying proteins on a surface, and an MFP removing proteins from a surface.

We recently extended the concept of the MFP significantly by using a novel vertical MFP technology (see Kaigala et al. and Fig. 3a). The vertical MFP enables a broad portfolio of research topics to be pursued, some of which include micro-immunohistochemistry on tissue sections (Fig. 3b), screening (bio)chemical libraries, and investigating cells as well as cellular architectures.