3822 - Diagnostic or laboratory reagents on a backing, prepared diagnostic or laboratory reagents whether or not on a backing, whether or not put up in the form of kits, other than those of heading 3006; certified reference materials:

Heading 3822 encompasses a broad range of diagnostic and laboratory reagents. These are substances or preparations specifically designed for use in medical, scientific, or industrial laboratory testing and analysis. The key characteristic is their intended application as a tool for diagnosis or research, distinguishing them from raw chemical materials or finished pharmaceutical products that are intended for therapeutic use. This heading covers both reagents presented on a backing material, such as in test strips or slides, and those in liquid, powder, or solid form, irrespective of whether they are packaged as a kit for specific diagnostic purposes.

Unlike headings within Section I (Live Animals; Animal Products) or other chapters dealing with basic chemicals, heading 3822 focuses on the specialized, often complex, chemical preparations used for analytical procedures. For instance, while other headings might cover bulk chemicals or basic laboratory glassware, 3822 is reserved for the functional reagents that enable specific tests, such as those detecting disease markers, measuring chemical concentrations, or identifying unknown substances in a laboratory setting.

Within heading 3822, two primary subcategories exist. The first, generally classified under 3822.10, covers prepared diagnostic or laboratory reagents. This is the most common classification for items like enzyme immunoassay kits, PCR reagents, or stain solutions used in microscopy. The second subcategory, 3822.90, is specifically for certified reference materials. These are materials with accurately established properties, used for calibration and quality control in analytical laboratories, ensuring the reliability and comparability of test results across different facilities.