SureCount™ standards are suspensions of polymer microspheres intended for the validation and monitoring of particle counters and supporting sample preparation processes. SureCount™ standards are available in diameters of 3µm, 5µm, 10µm, and 15µm, and the diameters are traceable to NIST Standard Reference Materials. The standards are supplied as ~1 x 106 microspheres/ml aqueous suspensions in 10ml volumes, and each bottle is provided with a Certificate of Traceability.