Frequently Asked Questions

Q-Plex technology is a multiplex ELISA, an assay platform that can simultaneously quantify the concentrations of multiple analytes by utilizing enzymes and adsorbed antibodies and/or antigens. Each fully-quantitative Q-Plex kit consists of arrays of up to 20 distinct capture antibody nano spots deposited into each well of a microtitre plate, meaning that in a 96-well plate, you can obtain up to 96 X 20 = 1920 data points. This is different from a traditional ELISA, where an entire well is devoted to a single type of antibody population, such that only 96 data points are acquired in one plate. Q-Plex kits can be imaged and analyzed using our high-quality, low-cost Q-View imager, or other imagers, and our Q-View Software.

The Q-Plex kits consist of a printed array of capture antibodies for a variety of biological markers. The user adds a calibrator and samples to individual wells of a 96-well plate. After incubation and washing, a mixture of biotinylated antibodies is added to the plate. This is followed by incubating with streptavidin-HRP or IR dye and is completed by capturing the light produced from adding chemiluminescent substrate with an imaging system. Pixel intensity values from the images are used to construct a standard curve and calculate the concentrations of the unknown sample for each system. 

The LLD is the lowest concentration of an analyte where its signal is distinguishable from the background (2 times the standard deviation of the mean of the background). This is different than the lower limit of quantification (LLOQ) which is the lowest concentration of an analyte that can be accurately measured. In many cases, the typical standard curve does not reach the LLD nor the LLOQ for a given protein. The user has an option of using additional dilutions of the calibrator mix to achieve the lower limit of quantification (LLOQ) for a given protein. A quick determination of LLOQ is to examine the backfit of your regression analysis and determine where the model no longer predicts within 80-120% of the actual standard value. I.E. the LLOQ is the lowest point where the backfit is within 80-120% of its corresponding value on the standard curve.

Q-View Software allows the user to open the plate image, mark the spots, input well assignments and select the product type. The software then automatically analyzes the pixel intensity of individual spots on the plate and processes the data. All customers can download a free trial of the software and have full access for 60 days. After 60 days, the software will still process images and calculate raw data but will no longer perform regression analysis. Visit our Q-View Software page to learn more about the software and how to start your free trial.

 The user will need to provide a pipette and imager. For convenient processing, we also recommend an automatic plate washer and multichannel pipette for best results.

Yes, different CCD and CMOS cameras give different pixel intensities based on the sensitivity of the camera. However, this will not affect assay performance or standard curve generation as the pixel intensities are relative values.

Yes, your samples can be mailed to Quansys where they will be tested using the Quansys Multiplex ELISA platform. Data, along with statistical analyses will be provided to the user within two weeks. Please contact us for details and pricing.