Analytical element for whole blood

• US 5,393,493 A
• Filed: 12/15/1992
• Issued: 02/28/1995
• Est. Priority Date: 02/09/1989
• Status: Expired due to Term

• Current Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Hora, Naofumi, Terashima, Kaoru, Makino, Yoshihiko, Kitani, Toru
• Primary Examiner(s): Housel, James C.
• Assistant Examiner(s): Soderquist, Arlen
• Application Number:
  US07/993,459
• Time in Patent Office: 805 Days
• Field of Search: 422/56, 422/57, 422/60, 436/170
• US Class Current: 422/422
• CPC Class Codes: C12Q 1/48 involving transferase
• CPC Class Codes: C12Q 1/60 involving cholesterol
• CPC Class Codes: G01N 33/525 Multi-layer analytical elements

Abstract

An integral multilayer analytical element in which a first fibrous porous layer, a nonfibrous porous layer, and a second fibrous porous layer superposed in this order on a water-impermeable light-transmissive support the first fibrous porous-layer having a larger pore size than the nonfibrous porous layer. The above three porous layers are integrally laminated to each other substantially closely by an adhesive discontinuously disposed so as to form microspaces continuing through from one layer to the next so as not to interfere with the approximately uniform permeation of liquid. A reagent composition which produces an optically detectable change in the presence of an analyte is incorporated in at least one of said three porous layers. When a nonporous reagent layer is incorporated on the support in the above analytical element, the reagent composition is incorporated in the nonporous reagent layer. By using the analytical element of the invention, the analytical values of various analytes of blood samples can be obtained independently of hematocrit values from whole blood samples and blood plasma samples in the range of the hematocrit values of 0% to 55%.

Claims

1. An integral multilayer analytical element which comprises a first fibrous porous layer, a nonfibrous porous layer of a membrane filter composed of a blushed polymer prepared by a phase separation method, a free side surface of the filter being disposed on the side facing the first fibrous porous layer, a pore size of the filter being the smallest in the vicinity of the free surface, and a second fibrous porous layer superposed in this order onto a water-impermeable light-transmissive support, the second fibrous porous layer and the nonfibrous porous layer acting as a blood cell separating layer which limits a hematocrit value of a blood sample from effecting an analysis thereof, the above three porous layers being integrally laminated to each other substantially closely by an adhesive discontinuously disposed so as to form microspaces continuing through from one layer to the next so as not to interfere with the approximately uniform permeation of liquid, and a reagent composition which produces an optically detectable change in the presence of an analyte being incorporated in at least one of said three porous layers wherein the first fibrous porous layer has a pore size which is larger than the pore size of the nonfibrous porous layer.

2. The analytical element of claim 1 wherein said reagent composition is incorporated in the first fibrous porous layer.

3. An integral multilayer analytical element which comprises a nonporous reagent layer, a first fibrous porous layer, a nonfibrous porous layer of a membrane filter composed of a blushed polymer prepared by a phase separation method, a free side surface of the filter being disposed on the side facing the first fibrous porous layer, a pore size of the filter being the smallest in the vicinity of the free surface, and a second fibrous porous layer superposed in this order onto a water-impermeable light-transmissive support, the second fibrous porous layer and the nonfibrous porous layer acting as a blood cell separating layer which limits a hematocrit value of a blood sample from effecting an analysis thereof, the nonporous reagent layer containing a hydrophilic polymer as a binder, the above three porous layers being integrally laminated to each other substantially closely by an adhesive discontinuously disposed so as to form microspaces continuing through from one layer to the next so as not to interfere with the approximately uniform permeation of liquid, and a reagent composition which produces an optically detectable change in the presence of an analyte being incorporated at least in said nonporous reagent layer, wherein the first fibrous porous layer has a pore size which is larger than the pore size of the nonfibrous porous layer.

4. The analytical element of claim 3 wherein said reagent composition is incorporated in the nonporous reagent layer and the first fibrous porous layer.

5. The analytical element of claim 3 wherein substantially the whole reagent composition is incorporated in the nonporous reagent layer.