Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving transferase
Reexamination Certificate
2006-11-21
2006-11-21
Saucier, Sandra E. (Department: 1651)
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving transferase
Reexamination Certificate
active
07138250
ABSTRACT:
The present invention provides a method of determining thiopurine methyltransferase (TPMT) activity in a subject. The method includes the steps of reacting sample obtained from the subject with a thiopurine derivative that is not 6-mercaptopurine to produce a methylated purine product; contacting the reacted sample with acid, thereby precipitating proteinaceous material from the reacted sample; separating supernatant from the precipitated proteinaceous material; and detecting in the supernatant the methylated purine product, where the amount of the methylated purine product indicates a level of thiopurine methyltransferase activity in the subject. In a method of the invention, the subject can be, for example, an inflammatory bowel disease patient. In one embodiment, the acid used to precipitate proteinaceous material is perchloric acid, for example, 70% perchloric acid. In another embodiment, the thiopurine derivative used as a substrate is 6-thioguanine. In a further embodiment, the methylated purine product is detected by fluorescence, which can be combined, if desired, with high performance liquid chromatography (HPLC).
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Prometheus Laboratories Inc.
Saucier Sandra E.
Townsend and Townsend / and Crew LLP
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