This product line is intended for researchers who are developing lateral flow diagnostic tests, and for other scientific investigations in diagnostics and biotechnology where labeling and detection of very low concentrations of substances is required. Microspheres are available with black, blue and red visual colors and four different bright fluorescent colors. Carboxylate modified surface functionalities are available. The diameter coefficient of variation (C.V.) of the microspheres is less than 5%, ensuring uniform migration through membranes. The microspheres are 0.4 or 0,85 micrometers nominal diameter, where the first is an optimal size for most latex-based lateral flow tests. They are prepared without detergents so they can be used immediately without pre-cleaning. Color-Rich particles are loaded with up to 25 % dye by weight, much more than other comparable products. This results in high intensity particles that give superior test sensitivity in qualitative lateral flow applications. The introduction of quantitative lateral flow tests has created a need for colored and fluorescent microspheres that are designed specifically for this new technology. In addition to our high intensity colored products, we offer the same microspheres dyed with bright fluorescent dyes.