Abstract: There are provided a recombinant cell that enables efficient production of protein, a method for producing the same, and a method for producing protein by using the cell. The cell is a mammalian cell having integrated therein 3 or more expression units containing an exogenous gene of interest, wherein gap elements are provided among multiple expression units, wherein the gap elements are designed to have chain lengths of 0.5 kbp or more, and the gap elements are mutually different sequences. Such a cell can produce recombinant protein stably for a long period and, especially, can show a strong positive linear correlation between the number of genes of interest introduced therein and the expression levels.

Abstract: Disclosed is a DNA construct that is useful for efficient generation of recombinant CHO cells useful for the production of target proteins. The DNA construct is a construct comprising, from a 5? end toward a 3? end, a first homologous DNA fragment, a target protein gene, and a second homologous DNA fragment. The first and second homologous DNA fragments have homology allowing for homologous recombination with a part of a hypoxanthine-phosphoribosyltransferase enzyme (hprt) locus in a CHO cell genome and have a chain length of not less than 1 kbp.

Abstract: Disclosed is a DNA construct that is useful for efficient production of recombinant CHO cells useful for the production of target proteins. The DNA construct is a construct comprising, from a 5? end toward a 3? end, a first homologous DNA fragment, a target protein gene, and a second homologous DNA fragment. The first and second homologous DNA fragments have homology allowing for homologous recombination with a part of a hypoxanthine-phosphoribosyltransferase enzyme (hprt) locus in a CHO cell genome and have a chain length of not less than 1 kbp.

Abstract: This invention provides a method for detecting an analyte, which, in specific detection of an analyte using photocurrent that is generated by photoexcitation of a sensitizing dye, can significantly simplify the structure and a detection procedure of a sensor unit and a device using the sensor unit and can realize detection with high accuracy, and also provides a sensor unit and a device using the sensor unit. According to the method, an analyte-containing sample solution and a sensitizing dye are brought into contact with the surface of a working electrode to immobilize the sensitizing dye onto the working electrode through specific binding. Subsequently, an electrolyte is supplied in situ while allowing the sample solution to be held without being removed to bring the working electrode and a counter electrode into contact with the electrolyte.

Abstract: There is disclosed an electrolyte medium which makes it possible to significantly simplify device structure and detection procedure as well as to detect photocurrent with high sensitivity and accuracy, in specific detection of an analyte with use of photocurrent generated by photo-excitation of a sensitizing dye. The electrolyte-containing sheet comprises a hydrous substrate; and an electrolyte contained in the hydrous substrate. The electrolyte-containing sheet is used as an electrolyte medium in specific detection of an analyte with use of photocurrent generated by photo-excitation of a sensitizing dye. A gel matrix or a water-absorbent substrate can be used as the hydrous substrate.