Plates microfluidic well

A Microfluidic Well Plate for High-Throughput Solid/Liquid Separations... 

Figure 5 (a) Top view of the microfluidic well plate for high-throughput solid/liquid separations. (b) Three-dimensional shape of the cavities, (c) Side view of one cavity. The narrow channel between source- and target-well allows passage of liquid, but does not allow passage of the solid-sample component (gel spot)... 

A novel 24-channel HPLC by Nanostream called Veloce was introduced at PITTCON 04. The column cassette contains 24 parallel microbore columns. The eluted samples are detected by a 24-channel UV filter photometer. The advantage of such a system is that it allows one to work with multiple samples simultaneously. Other interesting systems for parallel HPLC were those introduced by Eksigent, based on microfluidic flow control, and Sepiatec GmbH, which allows the processing of 75 multiple-well plates. 

D.L. Chen, R.F. Ismagilov, Microfluidic cartridges preloaded with nanoliter plugs of reagents An alternative to 96-well plates for screening, Curr. Opin. Chem. Biol. 10(2006) 226-231. 

Recently (2004), Applied Biosystems have introduced microfluidics cards or low-density gene expression arrays. These cards follow the main Taqman principles, but are based on a 384-well plate design. Therefore, multiple samples and genes can be monitored, quantitatively, at the same time. Maley et al. (2004) have also reported the use of a multiplexed Taqman model for high throughput screening applications. 

Many assays that have been bead-captured and gel-based have been converted to 96-well polystyrene microtiter plates to standardize the format for automation and higher throughput. In many ways, plate formats are a bridge to the higher-density microarray formats and remain quite useful until full conversion to microarray or microfluidic formats can be made. Microtiter plate assays or activated microbeads (i.e., Luminex) for panels of cytokines are widely available because of their use in clinical medicine. 

However, it has to be kept in mind that the main motivations for the application of assays based on microfluidics and microarrays are (i) their ability to enable experiments with biological samples that are only available in very small quantities (few microliters), and (ii) the reduction of the number of liquid-handling steps compared to the same assay in a well plate. These aspects are further discussed in Section 3. 

As consequence of implementation of parallelization in microfluidic cell culture chips, detection of biologically relevant cellular parameters imposes further requirements on the development of the applied detection techniques. Using available motorized microscope stages, time-lapse fluorescence microscopy is a widely applied technique in monitoring cellular responses. Alternatively, fluorescent plate readers facilitate real-time monitoring in highly parallelized systems (readouts for 1,536 well microtiter plate format). 

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