A/C Diagnostics has patents covering all aspects of the A/C Enzymatic Homocysteine Assay:

US Patent Nos. 5,985,540, 5,998,191, 6,066,467, 6,140,102, 6,468,762, 6,448,446, 6,713,273. Japan Patent No. 3,337,693. European Patent No. 1,265,846. Australia Patent No. 758,729, 229,460 and China Patent # 98807531.8.


Enzymatic Homocysteine Assay

  1. Stern, P.H., Mecham, J.O. and Hoffman, R.M.   Preparation of [35S]homocysteine thiolactone free of [35S]methionine.  J. Biochemical and Biophysical Methods 7, 83‑88, 1982. [PDF]

  2. Stern, P.H. and Hoffman, R.M. The chemical synthesis of high specific‑activity [35S]adenosylhomocysteine.  Analytical Biochem. 158, 408‑412, 1986. [PDF]

  3. Hoffman, R.M.  Is methioninase useful for the prevention of hyperhomocysteinemia-associated cardiovascular disease? In: Homocysteine Metabolism: From Basic Science to Clinical Medicine, pp. 155-156.  I. Graham, H. Refsum, I.H. Rosenberg, P.M. Ueland, eds.  Massachusetts: Kluwer Academic Publishers, 1997. [PDF]

  4. Han, Q., Lenz, M., Tan, Y., Xu, M., Sun, X., Tan, X-Z., Tan, X-Y., Tang, L., Miljkovic, D., and Hoffman, R.M.  High expression, purification, and properties of recombinant homocysteine a,g-lyase.  Protein Expression & Purification 14, 267-274, 1998. [PDF]

  5. Tan, Y., Tang, L., Sun, X., Zhang, N., Han, Q., Xu, M., Baranov, E., Tan, X-Z., Tan, X-Y., Rashidi, B., An, Z., Perry, A.W., and Hoffman, R.M.  Total-homocysteine enzymatic assay.  Clinical Chemistry 46, 1686-1688, 2000. [PDF]

  6. Tan, Y., Sun, X., Tang, L., Zhang, N., Han, Q., Xu, M., Tan, X., Tan, X., Hoffman, R.M.  Automated enzymatic assay for homocysteine.  Clinical Chemistry 49, 1029-1030, 2003. [PDF]

  7. A/C gets US nod to sell “cheapest” homocysteine test.  Clinica, Issue 1070, August 15, 2003. [PDF]

  8. Han, Q., Sun, X., Xu, M., Zhang, N., Tang, L., Tan, Y., and R.M. Hoffman.  3-deazaadenosine, a stabilizer of whole-blood homocysteine content, does not interfere with the single-enzyme homocysteine assay while totally inhibiting the enzyme conversion homocysteine immunoassay.  Clinical Chemistry 50, 1703-1704, 2004.[PDF]

  9. Tan, Y., and Hoffman, R.M.  A highly sensitive single-enzyme homocysteine assay.  Nature Protocols 3, 1388-1394, 2008. [PDF] Suppl. [PDF]

Vitamin B6 Enzymatic Assay

1.Leklem, J.E. Vitamin B6. In: Machlin, L. (ed.): Handbook of Vitamins, pp. 341-392. Marcel Dekker, New York (1991).

2.John RA. Pyridoxal phosphate-dependent enzymes. Biochem. Biophys. Acta 1248, 81-96. 1995.

3.Huq MD., Tsai N., Lin Y., Higgins L., and Wei L., Vitamin B6 conjugation to nuclear corepressor RIP 140 and its role in gene regulation. Nat. Chem. Biol.(2007) 3, 161-165.

4.Chang,  AJ., Huang, YC., Hsiao, LJ., Lee, YC., and Hsuen, SY. Determination of Vitamin B-6 Estimated Average Requirment and Recommended Dietary Allowance for Children Aged 7-12 Years Using Vitamin B-6 Intake, Nutritional Status and Anthropometry. J Nutr. 2002 Oct;132(10):3130-4.

5.Joosten E, Van den A, Riezler R, Naurath HJ, Lindenbaum J, and Stabler SP, et al. Metabolic evidence that deficiencies of vitamin B12 cobalamin, folate and vitamin B6 occur commonly in elderly people. American Journal of Clinical Nutrition 1993;58:468-76.

6.Morris MS, Picciano MF, Jacques PF, Selhub J.  Plasma pyridoxal 5'-phosphate in the US population: the National Health and Nutrition Examination Survey, 2003-2004. Am J Clin Nutr 87, 1446-1454, (2008)

7.Hron G, Lombardi R, Eichinger S, Lecchi A, Kyrle PA and Cattaneo M. Low vitamin B6 levels and the risk of recurrent venous thromboembolism The hematology journal 2007; 92(09), 1254-57.

8.Han, Q, et al.  High expression, purification, and properties of recombinant homocysteine a, g-lyase.  Protein Expr Purif 14, 267-274 (1998).

9.Han Q, Xu M, Tang L, Tan X-Z, Tan X-Y, Tan Y, Hoffman RM.  Homogeneous nonradioactive enzymatic assay for plasma pyridoxal 5-phosphate.  Clin Chem 48, 1560-1564 (2002).

10.Han, Q. and Hoffman, RM. Nonradioactive enzymatic assay for plasma and serum vitamin B6. Nature Protocols V. 3, No. 12 1815—19 (2008).

Enzymatic Cysteine Assay

  1. Han, Q., Xu, M., Tang, L., Sun, X., Zhang, N., Tan, X-H., Tan, X-Y., Tan, Y., and Hoffman, R.M.  Homogeneous enzymatic colorimetric assay for total cysteine. Clinical Chemistry 50, 1229-1231, 2004. [PDF]

  2. Han, Q., and Hoffman, R.M. Enzymatic assay for total plasma Cys. Nature Protocols 3, 1778-1781, 2008. [PDF]