Dry analytical element and method for the detection of prostatic acid phosphatase
AssigneeJohnson & Johnson Clinical Diagnostic Systems, Inc.
InventorsThomas Charles Arter, Mohan S Saini
Life of this patent
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Abstract
A dry analytical element has been prepared for the assay of prostatic acid phosphatase at a pH of from about 3 to about 6.5. The element can be a single porous spreading zone or a multilayer structure. Within the element is a relatively nonhygroscopic aromatic phosphate substrate for the analyte which produces a phenol reaction product. This product is reacted with a diazonium or tetrazolium salt, also in the element, to produce a chromophore for detection. A buffer in the element maintains it at the proper pH during the assay.
Claims18
An analytical element useful for the determination of prostatic acid phosphatase in an aqueous specimen comprising:
- a porous spreading zone containing
- (a) a nonhygroscopic aromatic phosphate which reacts as a substrate with prostatic acid phosphatase to produce a phenol reaction product, said nonhygroscopic aromatic phosphate substrate being an alkaline earth salt of an aryl phosphate ester, and
- (b) a diazonium or tetrazolium salt which is capable of reacting with said phenol reaction product to provide a chromophore,
- said element further comprising a buffer which maintains said element at a pH of from about 3 to about 6.5 when contacted with an aqueous specimen.
A multilayer analytical element for the determination of prostatic acid phosphatase comprising a nonporous, transparent support having thereon, in order and in fluid contact:
- a reagent layer containing a buffer which maintains said element at a pH of from about 3 to about 6.5 when contacted with an aqueous specimen, and
- a porous spreading layer containing
- (a) a nonhygroscopic aromatic phosphate which reacts as a substrate with prostatic acid phosphatase to produce a phenol reaction product, said nonhygroscopic aromatic phosphate substrate being an alkaline earth salt of an aryl phosphate ester, and
- (b) a diazonium or tetrazolium salt which is capable of reacting with said phenol reaction product to provide a chromophore.
A method for the determination of prostatic acid phosphatase comprising the steps of:
- A) contacting an aqueous specimen suspected of containing prostatic acid phosphatase with an analytical element comprising:
- a porous spreading zone containing
- (a) a nonhygroscopic aromatic phosphate which reacts as a substrate with prostatic acid phosphatase to produce a phenol reaction product, said nonhydroscopic aromatic phosphate substrate being an alkaline earth salt of an aryl phosphate ester, and
- (b) a diazonium or tetrazolium salt which is capable of reacting with said phenol reaction product to provide a chromophore,
- said element further comprising a buffer which maintains said element at a pH of from about 3 to about 6.5 during contact with said specimen, and
- B) detecting the formation of said chromophore as an indication of the presence of prostatic acid phosphatase in said specimen.
A method for providing a storage stable analytical element useful for the determination of prostatic acid phosphatase comprising:
- A) applying a reagent layer formulation containing:
- an accelerator, and
- a buffer which maintains said element at a pH of from about 3 to about 6.5 when contacted with an aqueous specimen,
- to a nonporous, transparent support,
- B) applying a subbing layer formulation to said reagent layer, and
- C) applying a porous spreading layer formulation to said subbing layer, said spreading layer containing
- (a) a nonhygroscopic aromatic phosphate which reacts as a substrate with prostatic acid phosphatase to produce a phenol reaction product, said nonhydroscopic aromatic phosphate substrate being an alkaline earth salt of an aryl phosphate ester, and
- (b) a diazonium or tetrazolium salt which is capable of reacting with said phenol reaction product to provide a chromophore.
Dependencies are inferred from the claim text.