assaycard

An assay card, or card-based assay device, is a disposable, flat card designed to perform one or more biochemical assays within a compact, self-contained format. The card typically contains multiple reaction chambers or wells, interconnected by microfluidic channels, and is preloaded with reagents or designed to receive reagents from the user. Samples are introduced through a designated port, after which capillary action, centrifugal force, or user-initiated actuation moves fluids through the channels to mix and trigger the assay reactions. Readouts are usually achieved optically, through colorimetric or fluorescent signals, or electrochemically, either directly on the card with integrated detectors or via an external reader.

Designs vary widely but common goals include minimizing sample volume, enabling multiplexing, reducing instrument requirements, and improving safety by containing reagents and waste on the card. Cards may be operated at ambient temperature or may include onboard heating for enzymatic reactions. Stability of reagents, storage life, and ease of manufacturing are important considerations in development.

Applications span clinical diagnostics, environmental monitoring, food safety, and research. Card-based assays are used for point-of-care tests, rapid screening, and educational purposes, offering rapid turnaround times and the potential for low-cost, portable testing in resource-limited settings. As microfluidic and materials technologies advance, assay cards increasingly integrate with compact readers and digital data systems to broaden access to rapid testing in resource-limited settings.