Multiplex assay kits

Contracting authority is publishing direct award notice for 'Multiplex assay kits'.

BACKGROUND INFO Running serological immunoassays the traditional way (ELISA) for multiple antigens consumes great volumes of unique serum samples and antigens. In large scale association studies, multiple antigens from several different pathogens that are believed to be related to the onset of diseases are run to compare antibody levels in healthy and affected individuals to show associations. Multiplexed methods are a high throughput sample saving alternative for ELISA that are more expensive reagent-wise but save a lot of hands-on time in the laboratory and in data input and analysis. There are several different approaches to multiplexing serological assays, the most common ones including Luminex assays (bead-based), and ELISA-like assays, in which several different antigens are printed to the bottoms of the wells. All commercially available multiplexing systems require specialized equipment. Several years ago TAU Faculty of Medicine and health technology purchased Meso Scale Discovery (MSD) Quickplex SQ120 instrument, which allows one to read MSDs commercially available multiplexed assay kits. MSD also sells UPLEX assay development kits, that enables one to bind up to 10 different types of biotinylated molecules on the bottom of each well in a 96-well format. Virology research group used this UPLEX platform to make our own custom assays from more than 50 different antigens, that can be mixed and matched in groups of 10 to suit particular needs in immunological studies. So far two studies has been published with main focus on using this platform and are in the process of running thousands of samples with up to 40 different antigens. NEED The scale of our association studies requires university to run thousands of cohort serum samples that are unique and limited in volume. This necessitates the use of multiplexing technologies as the existing sample volume would be insufficient to test with so many antigens if run individually. University has calculated a reagent price of 7.5€ per sample per well (assuming 10 antigens), which takes into account the price of antigens that we have ordered or produced ourselves. If university had a spotter robot and a reader, we could print our own plates and potentially get the reagent prices down. Albeit, printing our own plates would add to more laboratory time and increase personnel costs. Printing is also less flexible as it would not allow for running different antigen panels using the same plate, which is possible with the UPLEX linking system. Similarly, moving to Luminex technology would also require investing into new equipment and the reagent costs would likely be greater still. The commercially available Luminex assays have also been found to be less sensitive than equivalent MSD ones, which might force us to use multiple serum dilutions. Furthermore, we are not aware of any Luminex/ bead-based kits that allow one to use their own antigens, while this should be technically possible. There is no guarantee that the results we have obtained so far using the MSD would be easily comparable to ones measured with other methods. University is aware that some companies and institutes offer custom printing and Luminex development services, but they are not considered a viable option: Printing services usually have a minimum order of 100 plates, even for testing purposes, and the price of printing becomes cheaper than the UPLEX development kits when the batch size is more than 10 000 plates for custom assays (and we would still need a new plate reader). Likewise, the institutions offering custom Luminex assays quote roughly a $100 for running a single sample with 10 antigens assuming you send them 96-114 samples (http://www.cytokines.com/luminex-multianalyte.php) for assays with standard reagents. MARKET ANALYSIS AND CONCLUSION FOR DIRECT AWARD Moving to a different multiplex platform would require costly investments to new equipment, cross-validation of results with MSD UPLEX and the alternative method, as well as training the lab techs for new the methodology. Furthermore, the currently ready data-analysis pipeline would also need to be heavily modified.