Abstract: A fractionating apparatus is used for fractionating sample into micro-structures different in size, and includes a fractionating unit formed with a fractionating passage; the fractionating passage is defined in a groove formed in a substrate of the fractionating unit, and pillar patches are formed in the groove at intervals wider than the gap among the pillar patches; while the sample is migrated through the fractionating passage, small-sized DNA molecules are trapped in the pillar patches, and large-sized DNA molecules are smoothly migrated through the wide intervals; this results in that the large-sized DNA molecules reaches the end of the fractionating passage faster than the small-sized DNA molecules without clogging.

Abstract: There is disclosed a separation device in which separation flow paths for allowing the passage of only molecules having a predetermined size and smaller sizes are disposed between two flow channels set apart by a partition; and a separation method using the device. According to the separation technique, substances having small sizes such as cells, nucleic acids and proteins can be separated by the use of a small amount of a sample in a short time with excellent resolution, and problems of clogging and the like can also be solved.

Abstract: There is provided separation techniques for separating samples in a short period of time by using a small amount of samples with excellent resolution, causing few problems such as clogging.

Abstract: A separator has a specimen separating area comprising a number of recesses defined in an inner wall of a flow passage through which a specimen passes. For separating nucleic acid and protein, the recesses have openings whose maximum diameter is 300 nm or less, and adjacent ones of the recesses are spaced at an average interval of 300 nm or less.

Abstract: A fractionating apparatus is used for fractionating sample into micro-structures different in size, and includes a fractionating unit formed with a fractionating passage; the fractionating passage is defined in a groove formed in a substrate of the fractionating unit, and pillar patches are formed in the groove at intervals wider than the gap among the pillar patches; while the sample is migrated through the fractionating passage, small-sized DNA molecules are trapped in the pillar patches, and large-sized DNA molecules are smoothly migrated through the wide intervals; this results in that the large-sized DNA molecules reaches the end of the fractionating passage faster than the small-sized DNA molecules without clogging.