Figure 4
From: Probing the luminal microenvironment of reconstituted epithelial microtissues
Probing the luminal pH of epithelial tissues.
(a) Sample images of the microfluidic device (left) used to produce 35 μm diameter PEG microparticles that swell to an average diameter of 45 μm in physiological buffers (right). (b) Confocal slices showing SNARF-conjugated PEG microparticles with pH-dependent fluorescent profiles (left) and corresponding calibration curve quantifying the ratiometric fluorescent intensity of the microparticles as a function of pH (right). Scale bars are 50 μm. (c) 10X confocal slice of a Caco-2 cyst exhibiting correct basal and apical polarization upon microparticle incorporation. (d) Sample 20X image of a Caco-2 cyst incorporating a SNARF-conjugated PEG microparticle within the luminal compartment and (e) quantification of luminal pH within cysts as opposed to surrounding pH outside cysts (n = 5) as determined by ratiometric fluorescent intensities of SNARF-conjugated PEG microparticles.
