A/C Enzymatic HCY Assay
The Only Single Enzyme HCY Assay
Applicable to Common Automatic and Portable Analyzers

A/C Diagnostics LLC
7917 Ostrow Street, San Diego, CA 92111 USA 
Telephone: (858)654-2555;  E-mail: all@anticancer.com
A/C Enzymatic HCY Assay has two reactions
First Reaction: Reduction and Enzymatic Reaction

Total homocysteine is treated with a reducing reagent (DTT) and then reacts with recombinant homocysteinease (rHCYase) to produce H2S.

Second Reaction: Color Reaction

The resulting  H2S combines with DBPDA to form a pre-chromophore, then is oxidized by an oxidant (Fe+3) to form a chromophore, which can be measured by an spectrophotometer at OD660nm or by a fluorescence reader at Ex 660 nm /Em 700 nm. Therefore , the concentration of tHCY can be determined directly.
First  Reaction
Reduction and
Enzymatic reaction
Second Reaction
Color reaction
L-homocysteine (S-S)
L-homocysteine (S-H)
H2S + a-ketobutyrate+ NH3                                
End-point read at OD 660 nm or
Ex 660 nm/ Em 700 nm

Principle of A/C  Enzymatic HCY Assay