DEVELOPMENT OF AN AUTOMATED HOMOCYSTEINE ASSAY

High plasma concentrations of homocysteine are correlated with increased risks for coronary heart disease, stroke, atherosclerosis and other diseases. Accurate assessment of homocysteine concentrations in the general population has been hindered by the high expense and specialized equipment characteristic of the presently available homocysteine methods. Catch Inc. has developed an inexpensive homogeneous technology for homcysteine measurement. High throughput testing on commonly available laboratory analyzers is now possible. Results correlate well with published and commercial methods. The assay involves first the reduction of disulfide bonds followed by the interconversion of homocysteine and cystathionine catalyzed by the enzymes cystathionine B-synthase and cystathionine B-lyase. The rate of pyruvate produced by the cycling reaction is proportional to homocysteine levels in plasma. Plasma levels of cystathionine are too low to interfere. Assay commercialization requires reagent simplification to enable use with high throughput clinical laboratory instruments. Use of TCEP in place of DTE may allow the use of a two-reagent system in place of the current three-reagent configuration. Reagent shelf life and on-board instrument stability will be achieved using dry powder and liquid stabilization techniques. Precision, correlation and other studies required for 510 K Clearances are part of this proposal.