Observation apparatus and observation method

Abstract

Provided are an observation apparatus and an observation method capable of selectively observing target particles as an observation target among two or more kinds of particles included in a suspension. An observation apparatus includes: a holding unit that holds a suspension in a state of being separated into a target layer including target particles as an observation target among two or more kinds of particles included in the suspension and a non-target layer including particles other than the target particles among the two or more kinds of particles, the suspension including the two or more kinds of particles having different relative magnitudes of specific gravity with respect to a liquid; an observation light source that causes observation light to be incident from a side of the target layer; an objective lens that is provided on the side of the target layer and magnifies an image of the target particles; and an imaging unit that captures the image of the target particles magnified by the objective lens. A depth of field of an optical system including the objective lens is smaller than a thickness of the target layer.

Dependencies are inferred from the claim text.