RESUMEN
The analytical performance of the Dimension XL clinical chemical system was evaluated. The XL is the latest addition to the Dimension family of instruments; it is a random access analyser with a throughput up to 740 tests/hour. Regression analysis of method comparison studies with Dimension AR yielded slopes of 0.93 to 1.03 and correlation coefficients >/=0.96 for 28 assays. Excellent precision performance was also observed. New instrument features of the XL are discussed.
RESUMEN
We have used chromium dioxide magnetic particles as the solid support in developing a series of immunological tests. The high surface area (greater than 40 m2/g) available on the magnetic particles and their easy dispersion throughout a solution allow for rapid and complete capture of the target antigen. The magnetic responsiveness of the particles allows for rapid, high-efficiency washing to reduce nonspecific binding, which often limits the sensitivity of serological assays. These features form the basis of extremely rapid and flexible assays for several hormones and markers of cancer and infectious disease. Most of the assays involve monoclonal antibodies. Here we describe specific performance characteristics for thyroxin, follitropin, creatine kinase isoenzyme MB, and antibody to human immunodeficiency virus (HIV). All of the assays are performed in less than 90 min, many in 30 to 45 min. The technology is highly flexible and is suitable for a variety of formats, from manual to fully automated.