Container set and sample preparation method using same
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.
1. A method for preparing a sample for analysis from a specimen, comprising the steps, in order, of:
fixing a specific substance in the specimen to a solid surface;
removing impurities that are not fixed to the solid surface by centrifugal filtration;
releasing away a substance to be collected from the specific substance fixed to the solid surface to a liquid; and
collecting the substance to be collected that is released away in the liquid, wherein
the centrifugal filtration and release of the substance to be collected into the liquid are performed using the same filter unit,
the filter unit includes: a housing having two ends in which a sample introducing opening that may be closable is made at one of the two ends and a liquid discharging opening is made at another end; and a filter fixed to the housing,
the sample introducing opening is configured such that solids and liquids can be therethrough introduced into a sample holding space surrounded by the housing and the filter,
the liquid discharging opening is configured such that a filtrate transmitted through the filter can be therethrough discharged,
after the centrifugal filtration, the filter unit and a closing unit are joined to each other, so that the substance to be collected is released away into the liquid in a state that the liquid discharging opening is spatially closed,
the housing of the filter unit has a first joining portion,
the closing unit has a second joining portion that is configured to be joinable to the first joining portion,
the first joining portion of the filter unit and the second joining portion of the closing unit are configured such that the two joining portions are joinable to each other to produce an airtight state to close the liquid discharging opening spatially by the closing unit, and
the filter unit and the closing unit are further pushed to each other to shorten a distance between the filter and the closing unit while the state that the two joining portions are joined is maintained, so that a space between the closing unit and the filter is made into a positive pressure relative to a pressure in the sample holding space, and
the substance to be collected is released away into the liquid in this positive pressure state.
2. The method for preparing a sample for analysis according to claim 1 , wherein
after the substance to be collected is released away into the liquid, the filter unit and the closing unit are separated from each other, and
the liquid in which the substance to be collected is released away is collected by a centrifugal filtration.
3. The method for preparing a sample for analysis according to claim 1 , wherein
the specific substance fixed to the solid surface is a protein, and
by a proteolysis of the protein using a protease, a peptide fragment is released away, as the substance to be collected, into the liquid.
4. The method for preparing a sample for analysis according to claim 3 , wherein
the solid is a porous body, and the protein in the specimen is fixed into pores in the porous body, and
the protease fixed to surfaces of microparticles contacts the protein fixed into the pores in the porous body, so that the protein is site-specifically cleaved and the peptide fragment is released away into the liquid.