Rapid lateral flow tests: Considerations for product development

Lateral flow test strips based on the principles of immunochromatography exist for a wide array of target analytes. The first tests were made for the detection of human chorionic gonadotropin (hCG). Today, there are commercially available tests for monitoring ovulation, detecting infectious disease organisms, analyzing drugs of abuse, and measuring other analytes important to human physiology. Taking a lateral flow test strip from the design stage through product development to final manufacturing is a process that employs principles from biology, chemistry, physics, and engineering. A test design that works well in the R&D lab is of little use if it is difficult to manufacture reliably in high yield at reasonable cost. Similarly, even though a product may work well during in-house testing, if it fails to work reliably in the hands of the consumer, it is unlikely to be commercially successful. Uncharacterized variations in a single material, reagent, or process can be sufficient to ruin consistency of performance. With these considerations in mind, in this brochure, Merck provides information on the key aspects of immunochromatographic test strip design, the materials used, their integration with reagents, and manufacturing processes. Understanding these principles will help to provide a framework for more rapid test development.