The miniaturized SIA instruments (A, B, C) are the smallest automated analyzers in existence, with a footprint, size of an iPad. Their centerpiece is the lab-on-valve (LOV) manifold which serves as a conduit for all microfluidic manipulations. Miniaturized SIA systems use small volumes of sample and reagents (10 to 100microliters per assay), and perform assays at a high speed. Since lab-on-valve module is transparent, it allows instant visual control of all microfluidic manipulations (See movie clip 2.2.6.). Miniaturized SIA instruments are available in two configurations:
Single line system equipped with one pump (A, C)
Two line system served by two pumps (B)
The single line configuration will accommodates a majority of reagent based assays. The two line configuration will handle assays that use more than two reagents, or column separations, or gas diffusion methods, since the second pump supports a wider variety of microfluidic operations. The pump is the key component of SIA instrument because it must deliver a wide range of volumes, and flow rates, with a high precision and repeatability over long periods of time. This is why combination of synchronously refilling pump (miliGAT) controlled by advanced software (FloPro), was used to construct the single line miniSIA-1 (A) and the two line miniSIA-2 instrument (B), manufactured by Global FIA. The versatility of these instruments is documented by examples of reagent based assays described in this chapter (2.2.13.).
The single line microSI system, which uses the convectional syringe pump (C) is manufactured by FIAlab. It will automate the same tasks as instrument (A), albeit at lower sampling frequency, and by using a less convenient programming, since the script must accommodate pump refilling cycle.