Abstract: A novel D-serine quantification method that can overcome various disadvantages of a conventional D-serine quantification method; a novel enzyme that can be used in the D-serine quantification method; a gene encoding the enzyme; and the like. Specifically, a novel D-serine dehydratase including (a) a protein having an amino acid sequence set forth in SEQ ID NO: 1 or (b) a protein having an amino acid sequence homologous to the amino acid sequence set forth in SEQ ID NO: 1 and having a D-serine dehydratase activity; and a D-serine quantification method including the steps of reacting a sample with the enzyme, quantifying ammonia or pyruvic acid produced by the reaction, and calculating the amount of D-serine in the sample based on a value produced by the quantification.

Abstract: A novel D-serine quantification method that can overcome various disadvantages of a conventional D-serine quantification method; a novel enzyme that can be used in the D-serine quantification method; a gene encoding the enzyme; and the like. Specifically, a novel D-serine dehydratase including (a) a protein having an amino acid sequence set forth in SEQ ID NO: 1 or (b) a protein having an amino acid sequence homologous to the amino acid sequence set forth in SEQ ID NO: 1 and having a D-serine dehydratase activity; and a D-serine quantification method including the steps of reacting a sample with the enzyme, quantifying ammonia or pyruvic acid produced by the reaction, and calculating the amount of D-serine in the sample based on a value produced by the quantification.

Abstract: A novel D-serine quantification method that can overcome various disadvantages of a conventional D-serine quantification method; a novel enzyme that can be used in the D-serine quantification method; a gene encoding the enzyme; and the like. Specifically, a novel D-serine dehydratase including (a) a protein having an amino acid sequence set forth in SEQ ID NO: 1 or (b) a protein having an amino acid sequence homologous to the amino acid sequence set forth in SEQ ID NO: 1 and having a D-serine dehydratase activity; and a D-serine quantification method including the steps of reacting a sample with the enzyme, quantifying ammonia or pyruvic acid produced by the reaction, and calculating the amount of D-serine in the sample based on a value produced by the quantification.

Abstract: A method for detecting or measuring homocysteine in a sample includes the steps of (a) reacting a D-amino acid present in a sample with a D-amino acid converting enzyme to convert the D-amino acid into a substance that does not serve as a substrate of D-amino acid oxidase or D-amino acid acetyltransferase; (b) reducing homocysteine in the sample with a thiol compound; (c) reacting the reduced homocysteine with a methyltransferase and a methyl donor to newly produce D-amino acid; and (d) reacting the produced D-amino acid with the D-amino acid oxidase or the D-amino acid acetyltransferase in the presence of an SH reagent to produce hydrogen peroxide, and color-developing the produced hydrogen peroxide by using an oxidative color-developing agent.

Abstract: A method for detecting or measuring homocysteine in a sample includes the steps of (a) reacting a D-amino acid present in a sample with a D-amino acid converting enzyme to convert the D-amino acid into a substance that does not serve as a substrate of D-amino acid oxidase or D-amino acid acetyltransferase; (b) reducing homocysteine in the sample with a thiol compound; (c) reacting the reduced homocysteine with a methyltransferase and a methyl donor to newly produce D-amino acid; and (d) reacting the produced D-amino acid with the D-amino acid oxidase or the D-amino acid acetyltransferase in the presence of an SH reagent to produce hydrogen peroxide, and color-developing the produced hydrogen peroxide by using an oxidative color-developing agent.

Abstract: A chromatography assay device and method for use with whole blood samples utilizing a red blood cell separating agent to aggregate red blood cells and permit plasma or serum to flow by capillary action and a neutralizing agent to neutralize any effects the red blood cell separating agent may have on the device and method.

Abstract: An organism which generates energy through the decomposition of cellulose such as termites can be selectively destroyed with a fluorine-containing glycoside of the formula: ##STR1## wherein n is an even number of 2 to 20, and m is an integer of 0 to 5.

Abstract: A writing instrument internally houses a miniature electronic calculator which includes a key input section comprising a single key which is subjected to a rotational or translational movement to select one of a plurality of switches. When the key is depressed against a bias applied thereto while in a position in which it has selected one of the switches, the selected switch is controlled thereby to input an associated information into an arithmetic unit of the calculator. The instrument case or key is marked with indicia which designate the key positions for the convenience of selecting input informations. The key input section comprises an insulating substrate on which an array of a plurality of stationary contacts are formed along the direction of movement of the key, a flexible insulating film disposed in opposing relationship with the stationary contacts, and a movable contact deposited on the side of film which faces the stationary contacts so as to extend in the direction of movement of the key.