Slide printing techniques

Protein assays using ordered arrays emerged in the late 90s [13]. Recently Lahiri et al. introduced a technique which enables the fabrication of microarrays for membrane proteins [14]. Printed lipid microspots on y-aminopropylsilane slides have high mechanical stability, independent of whether the lipid is in the gel-or fluid-phase. They immobilized G-protein coupled receptors and studied their interaction with a set of inhibitors. 

It had been anticipated that there might be a difference in the fine structure of the replica in the area of the adsorbed acid clusters compared to that of the bare glass substrate. Enlarged prints of the best micrographs of this series showed no variation of texture between these areas. When replicas of cleaved mica, which is thought to be structureless, were prepared by the technique used here, they had a similar fine texture this suggests that the fine structure results from the shadowed replica itself and not from the actual surfaces of the monolayered slides. 

Another possible source of variation within slides is known as spatial bias. This describes any effect that influences the intensity of a spot based on its position on a slide, such as variations in hybridization efficiency over the slide surface, variations in slide flatness, and scanner focal depth across a slide as well as print-tip-dependent effects. Currently, two methods are used to deal with these The first is to divide the slide into subsections, typically subgrids from individual pins, and normalize each subset separately. Or, when the variation is not restricted to a regular subgrid, such as with slide flatness problems, a two-dimensional Lowess technique can be used (see the Lorenze Wernisch website in the appendix). This is a more complex form of the Lowess regression, where a polynomial surface is fitted to the data based on slide coordinates and the surface is then smoothed. The procedure can be run on either the log ratio, the signal intensity, or the background intensities. 

The 3D melt-plotting is a computer-aided technique used for the fabrication of patient-specific implants or scaffolds endowed with a porous stracture which allows cell infiltration and vascularisation. The object to print can be designed by software or it is retrieved from a diagnostic examination such as X-ray or computer tomography. A computer-aided design software models and decomposes the object into two 2D slides. Thus, the digital information is sent to a robotic device (ie, Bioscaffolder) which builds up the object layer by layer (Seyednejad et al., 2011). PCL is one of the most used... 

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