Abstract: A container set including: a filter unit; and a closing unit that is attachable to and detachable from the filter unit. The filter unit includes: a housing having a sample introduction opening provided at one end, and a liquid discharging opening provided at the second end; and a filter fixed to the housing. The housing has a first joining part, and the closing unit has a second joining part configured to be joinable with the first joining part. The first joining part and the second joining part are configured such that the liquid discharging opening is spatially closed in a state in which the two joining parts are joined together. A space between the closing unit and the filter is made into a positive pressure relative to a pressure in the sample holding space by pushing the filter unit and the closing unit such that the distance therebetween is shortened.

Abstract: The present invention provides a method for detecting a monoclonal antibody in a sample, the method comprising: (a) a step of capturing and immobilizing, in pores of a porous body, the monoclonal antibody in the sample; (b) a step of performing selective protease digestion of the monoclonal antibody for 30 min or longer by contacting the porous body having the monoclonal antibody immobilized thereon with nanoparticles having a protease immobilized thereon; and (c) a step of detecting a peptide fragment obtained by the selective protease digestion, using liquid chromatography mass spectrometry (LC-MS), wherein step (b) is carried out under stirring condition for 10 sec to 5 min in the initial reaction stage, and then under static condition. According to the present invention, the detection method of a monoclonal antibody using mass spectrometry is simplified and can be applicable to multisample analysis.

Abstract: A container set including: a filter unit; and a closing unit that is attachable to and detachable from the filter unit. The filter unit includes: a housing having a sample introduction opening provided at one end, and a liquid discharging opening provided at the second end; and a filter fixed to the housing. The housing has a first joining part, and the closing unit has a second joining part configured to be joinable with the first joining part. The first joining part and the second joining part are configured such that the liquid discharging opening is spatially closed in a state in which the two joining parts are joined together. A space between the closing unit and the filter is made into a positive pressure relative to a pressure in the sample holding space by pushing the filter unit and the closing unit such that the distance therebetween is shortened.

Abstract: The present invention provides a method for detecting a monoclonal antibody in a sample, the method comprising: (a) a step of capturing and immobilizing, in pores of a porous body, the monoclonal antibody in the sample; (b) a step of performing selective protease digestion of the monoclonal antibody for 30 min or longer by contacting the porous body having the monoclonal antibody immobilized thereon with nanoparticles having a protease immobilized thereon; and (c) a step of detecting a peptide fragment obtained by the selective protease digestion, using liquid chromatography mass spectrometry (LC-MS), wherein step (b) is carried out under stirring condition for 10 sec to 5 min in the initial reaction stage, and then under static condition. According to the present invention, the detection method of a monoclonal antibody using mass spectrometry is simplified and can be applicable to multisample analysis.

Abstract: The present invention provides a technique that can simultaneously analyze a plurality of antibody drugs and can be validated. The present invention provides a method of bringing a porous body in which monoclonal antibodies to be measured are immobilized in pores into contact in a liquid with nanoparticles on which proteases are immobilized and performing selective proteolysis of monoclonal antibodies to detect peptide fragments each comprising unique amino acid sequence derived from the Fab region of the monoclonal antibodies via liquid chromatography-mass spectrometry (LC-MS), wherein peptide fragments of two or more types of monoclonal antibodies in the same biological sample are simultaneously quantified.