초록 ▼

A chromatographic assay device according to the present invention provides a unidirectional immunoassay for an analyte in a whole blood sample with improved sensitivity and freedom from interference. Such a device comprises: (1) a first opposable component including: (a) a sample application zone co

A chromatographic assay device according to the present invention provides a unidirectional immunoassay for an analyte in a whole blood sample with improved sensitivity and freedom from interference. Such a device comprises: (1) a first opposable component including: (a) a sample application zone containing a matrix of porous material permeable to the liquid portion of blood but capable of trapping the cellular components of blood; and (b) a chromatographic medium having first and second ends and including: (i) a detection zone having immobilized thereon a first specific binding partner for the analyte; and (ii) a conjugate zone having a labeled second specific binding partner for the analyte in a resolubilizable form; the sample application zone being in operable contact with the first end of the chromatographic medium and the conjugate zone being located closer to the first end of the chromatographic medium than the detection zone; and (2) a second opposable component including: (a) an applicator; and (b) an absorber. In the device, the first and second opposable components are brought into operable contact to cause the applicator to come into operable contact with the sample application zone to apply a wash liquid thereto and cause the absorber to come into operable contact with the second end of the chromatographic medium. Also within the scope of the invention are multiplex devices that can perform more than one assay simultaneously and test kits.

대표청구항 ▼

A chromatographic assay device according to the present invention provides a unidirectional immunoassay for an analyte in a whole blood sample with improved sensitivity and freedom from interference. Such a device comprises: (1) a first opposable component including: (a) a sample application zone co

A chromatographic assay device according to the present invention provides a unidirectional immunoassay for an analyte in a whole blood sample with improved sensitivity and freedom from interference. Such a device comprises: (1) a first opposable component including: (a) a sample application zone containing a matrix of porous material permeable to the liquid portion of blood but capable of trapping the cellular components of blood; and (b) a chromatographic medium having first and second ends and including: (i) a detection zone having immobilized thereon a first specific binding partner for the analyte; and (ii) a conjugate zone having a labeled second specific binding partner for the analyte in a resolubilizable form; the sample application zone being in operable contact with the first end of the chromatographic medium and the conjugate zone being located closer to the first end of the chromatographic medium than the detection zone; and (2) a second opposable component including: (a) an applicator; and (b) an absorber. In the device, the first and second opposable components are brought into operable contact to cause the applicator to come into operable contact with the sample application zone to apply a wash liquid thereto and cause the absorber to come into operable contact with the second end of the chromatographic medium. Also within the scope of the invention are multiplex devices that can perform more than one assay simultaneously and test kits. ding a recombinant, heterologous gene in a genome of a mammalian cell, wherein the process comprises: (A) providing a mammalian cell having a recipient gene in its genome, wherein said recipient gene comprises complementing DNA comprising a first nucleotide sequence and a second nucleotide sequence downstream of said first nucleotide sequence; (B) transfecting said mammalian cell in vitro with a DNA comprising: (1) a third nucleotide sequence homologous to said first nucleotide sequence; (2) a fourth nucleotide sequence homologous to said second nucleotide sequence; and (3) a DNA sequence heterologous with respect to DNA in said recipient gene, wherein said heterologous DNA sequence is between said third and said fourth nucleotide sequences and said heterologous DNA sequence comprises a first insertion DNA sequence and a second insertion DNA sequence, wherein said first insertion DNA sequence comprises a first coding sequence that encodes a first product that does not confer resistance to a selection agent involved in the selection of transformants, and a regulatory sequence for regulating the expression of said first product, and said second insertion DNA sequence comprises a second coding sequence that encodes a second product that confers resistance to a selection agent involved in the selection of transformants, and a promoter allowing the expression of said second product in said mammalian cell; and (C) selecting a transfected cell in which said heterologous DNA sequence has been inserted between said first and said second nucleotide sequences in said recipient gene by homologous recombination with said third and said fourth nucleotide sequences to thereby provide a mammalian cell containing in its genome the recombinant, heterologous gene, and in addition, the second insertion DNA sequence encoding the selective agent. 2. The in vitro process as claimed in claim 1, wherein said regulatory sequence is a promoter. 3. The in vitro process as claimed in claim 1, wherein said regulatory sequence is an enhancer. 4. The in vitro process as claimed in claim 1, wherein insertion of said heterologous DNA in said recipient gene is accompanied by replacement of recipient gene DNA. 5. The in vitro process as claimed in claim 1, wherein said recipient gene contains a promoter, which is inactivated following insertion of said heterologous DNA sequence into said recipient gene. 6. The in vitro process as claimed in claim 1, wherein said recipient gene has a regulatory sequence and said coding sequence of said first insertion DNA sequence is under the control of said regulatory sequence following insertion of said heterologous DNA sequence into said recipient gene. 7. The in vitro process as claimed in claim 1, wherein expression of said recipient gene is under the control of said regulatory sequence following insertion of said heterologous DNA sequence in said recipient gene. 8. The in vitro process as claimed in claim 1, wherein each of said third and said fourth nucleotide sequences has a length greater than 150 base pairs and shorter than the length of said recipient gene. 9. The in vitro process as claimed in claim 1, wherein said recipient gene is present in said mammalian cell in at least two copies and said heterologous DNA sequence is inserted into only one copy of said recipient gene. 10. The in vitro process as claimed in claim 1, wherein said first coding sequence encodes an interferon, an interleukin, a β-3-adrenergic receptor, a retinoic acid receptor, an HIV receptor, or lac Z. 11. The in vitro process as claimed in claim 1, wherein said first coding sequence encodes lac Z. 12. The in vitro process as claimed in claim 1, wherein said mammalian cell is a mouse embryonic stem (E. S.) cell. 13. The in vitro process as claimed in claim 1, wherein said transfection is by electroporation. 14. The in vitro process as claimed in claim 1, which further comprises amplifying by polymerase chain reaction the heterologous