An automated method for preparing and amplifying a sequence contained in a nucleic acid present in a sample, the nucleic acid being prepared in a receptacle that is part of a unit that includes a plurality of receptacles and holds a removable contact-limiting element for aspirating a fluid component of the sample from the receptacle. The main compartment defines a substantially hollow first cavity. The fumaric acid-supported sheet is a sheet which supports fumaric acid particles having an average particle diameter of 30 \u03bcm or less, andor a sheet in which at least a part of constituent fibers is coated with fumaric acid. 0, M is dopant of a monovalent metal element and is included in phosphor by approximately 0<d\u22661000 wt-ppm. Otherwise, the testing stops with the just tested subset of cells having a stand-by current exceeding the certain value.