Abstract: Embodied is a flow cell that is for analysis of nucleic acid and that is capable of inhibiting complication of data processing without a reduction in throughput. The flow cell for analysis of nucleic acid comprises: a flow path formation body that has a flow path into which a nucleic acid sample flows; and a flow path formation body support member that has a region in which nucleic acid in a nucleic acid sample flowing into the flow path is to be adsorbed. The flow path formation body support member has the nucleic acid adsorption region in which nucleic acid is to be adsorbed, and a fluorescent particle adsorption region which is separated from the nucleic acid adsorption region, and in which fluorescent particles are to be adsorbed. In the fluorescent particle adsorption region, a blocking substance that can be specifically adsorbed to the fluorescent particle adsorption region is adsorbed.

Abstract: Provided is a particle quantitative measurement device according to which the number of particles that can be accurately recognized in a particulate sample has a wider range. An observation device 1 comprises a computer 108 and an imaging camera 107 for acquiring a sample image representing the particulate sample. As an extraction unit, the computer 108 extracts a low-brightness pixel for which I<M?k? is satisfied for brightness I from pixels of the sample image. Here, M represents brightness for a reference image, k represents a real positive number, and ? represents a standard deviation for the brightnesses of the pixels in the reference image. The computer 108 also functions as a particle recognition unit or a particle quantitative measurement unit and quantitatively measures the particulate sample on the basis of the low-brightness pixel.