TipChip: a modular, MEMS‐based platform for experimentation and phenotyping of tip‐growing cells

Abstract

Large-scale phenotyping of tip-growing cells such as pollen tubes has hitherto been limited to very crude parameters such as germination percentage and velocity of growth. To enable efficient and high-throughput execution of more sophisticated assays, an experimental platform, the TipChip, was developed based on microfluidic and microelectromechanical systems (MEMS) technology. The device allows positioning of pollen grains or fungal spores at the entrances of serially arranged microchannels equipped with microscopic experimental set-ups. The tip-growing cells (pollen tubes, filamentous yeast or fungal hyphae) may be exposed to chemical gradients, microstructural features, integrated biosensors or directional triggers within the modular microchannels. The device is compatible with Nomarski optics and fluorescence microscopy. Using this platform, we were able to answer several outstanding questions on pollen tube growth. We established that, unlike root hairs and fungal hyphae, pollen tubes do not have a directional memory. Furthermore, pollen tubes were found to be able to elongate in air, raising the question of how and where water is taken up by the cell. The platform opens new avenues for more efficient experimentation and large-scale phenotyping of tip-growing cells under precisely controlled, reproducible conditions.

AFM-based Mapping of the Elastic Properties of Cell Walls: at Tissue, Cellular, and Subcellular Resolutions

“…For measuring turgor pressure, we face similar challenges: a technique that measures at mesoscale resolution across tissues does not yet exist. The pressure microprobes used in plants were, up until recently, limited by the glass tip radius, which is the size of meristematic cells (5 µm) 12,21 . Another very promising avenue of research is to develop this AFM method for use on non-plasmolyzed tissue; we hope, in this way, to reveal the relation between single cell turgor pressure and tissue growth.…”

“…With the AFM, the required tissue, cellular, and subcellular resolutions can be achieved [8][9][10] . Recently several protocols have been developed specifically to measure mechanics of plants tissue that could also be used 11,12 .…”

Time-resolved NMR metabolomics of plant cells based on a microfluidic chip

“…Although microfluidic devices have been used to study different aspects of plant cell biology such as gene expression (Busch et al, 2012), cell biomechanics (Sanati Nezhad et al, 2013a, b), cellular mechanism of growth (Agudelo et al, 2013;Grossmann et al, 2011;Sanati Nezhad et al, 2014), phenotyping of plant organs (Jiang et al, 2014), and chemical stimulation of plant cells (Sanati Nezhad et al, 2013c), they had not been performed adequately enough with walled plant cells, so far. The reason is that these cells are not attached to a surface as mammalian cells, but have to be cultivated in suspension.…”

Quantification of cellular penetrative forces using lab-on-a-chip technology and finite element modeling

“…To quantitatively assess the invasive ability of the pollen tube, we adapted a previously developed lab-on-a-chip (LOC) called the TipChip (30)(31)(32). In the TipChip, pollen tubes are guided to elongate through narrow microchannels specifically designed to accommodate testing devices such as mechanical obstacles along its path.…”