Abstract: A method for checking for sensitivity of acetylcholine esterase in insects using a single insect, which comprises the steps, in any order, of homogenizing a single insect in aqueous neutral to acid pH phosphate buffer, producing a solution of acetylcholine iodide in neutral to acid pH phosphate buffered water-miscible organic solvent, producing a solution of 5,5-dithio-bis-(2-nitrobenzoic acid) in the buffer, and producing a solution of propoxur in the buffer, dropping the insect homogenisate into the wells of an assay plate, dropping the acetylcholine iodide and 5,5-dithio-bis-(2-nitrobenzoic acid) solutions into some of the wells and 5,5-dithio-bis-(2-nitrobenzoic acid) propoxur solutions into the other wells and checking for a difference in the yellow coloration between the samples in the two sets of cells.

Abstract: The invention relates mainly to a method of testing the activity of a potentially active substance to inhibit the enzymatic activity of phospholipase A2.

Abstract: A sensor for detecting an analyte enzyme includes at least one substrate compound and at least one indicator compound selected to produce a measurable change of state as a result of the interaction of the substrate and at least one target or analyte enzyme. Each of the indicator(s) and substrate(s) are incorporated within a single polymer.

Abstract: A process for enzymatically producing, from a vegetable oil deodorizer distillate, a dietary sterol fatty acid ester superior in flavor qualities (e.g., color, odor and taste) and safety and containing no or little trans fatty acids, wherein the conditions for treatment of the starting material, synthetic reaction and subsequent purification are controlled so that the sterol fatty acid ester becomes applicable as a daily food material, a health food material or a pharmaceutical material. In the process, fatty acid esters, e.g., triacylglycerol, in the vegetable oil deodorizer distillate are previously degraded by hydrolysis with a chemical catalyst, fatty acids produced in the hydrolysis are removed by molecular distillation to give a sterol-containing fraction. The sterol-containing fraction is added with any fat and oil primarily comprising triacylglycerol. The mixture is used as the starting material, and the synthetic reaction is performed under strictly controlled conditions using a lipolytic enzyme.

Abstract: A multilayer analytical element for determining a level of an analyte on a substrate and adapted for use with hydrogen peroxide and an affinity-enzymatic compound of formula A-C-B, wherein A is a detecting agent having affinity for the analyte, B is an enzymatic visualizing agent consisting of peroxidase and C is a binding agent linking the detecting and visualizing agents together. The multilayer analytical element of the invention comprises a solid support and a hydrophilic layer thereon, the hydrophilic layer being formed of gelatin, polyvinyl alcohol or a mixture thereof and containing a developing agent and a hydrophobic color-producing agent in a total amount of 5 to 30 weight %, the developing agent and the color-producing agent being present in a weight ratio of 1:0.3 to 1:3.0.

Abstract: Antimicrobial agents and method for isolation thereof from the gel liquid of Aloe vera includes at least one antimicrobial agent isolated from the clear gel isolated from the whole leaf of the Aloe vera plant, wherein the antimicrobial agent is an agent produced by the Aloe vera and/or indigenous bacteria that colonize the Aloe vera plant, is disclosed.

Abstract: A method for the diagnosis of Alzheimer's disease (AD) in a patient, comprising the steps of: (1) providing a sample of an appropriate body fluid from said patient; (2) detecting the presence of acetylcholinesterase (AChE) with an altered glycosylation pattern in said sample. It has been established that approximately 75-95% of the AChE in the CSF of AD patients binds to Concanavalin (Con A) or wheat germ agglutinin (WGA) but with different specificity to each. Accordingly, in order to identify the glycosylation pattern of AChE in the sample, the binding to Con A is determined, then the binding to WGA is determined, and a ratio calculated. The ratio is characteristic of the glycosylation pattern. In alternative embodiment of the invention a monoclonal antibody specific for AChE with an altered glycosylation pattern is used to detect its presence.

Abstract: The present invention provides novel methods and diagnostic kits for the objective measurement of the severity of pain or stress being experienced by a patient with a disorder, diagnosis and treatment for patients suffering from painful disorders, and monitoring the effectiveness of different pain-treatment protocols. Pain-measuring methods comprise collecting a sample from a patient and determining the presence of a pain-associated marker in the sample. Methods for alleviating pain comprise administrating a dose of a therapeutically effective amount of a composition to the patient wherein the dose is determined by the presence of a pain-associated marker in a biological sample obtained from the patient. Compositions for alleviating pain comprise substances that are pain-associated markers or agents that interfere with pain-associated markers, and block or modulate the progression of pain perceived by the patient.

Abstract: Methods, compositions and materials useful in the detection of organophosphorous and organosulfur compounds are disclosed. In particular, biosensors wherein a porous or a non-porous support having an enzyme immobilized upon or within are disclosed. The biosensors exhibit enzymatic stability at extreme temperatures and/or denaturing conditions, and similar kinetic characteristics of the soluble form of the enzymes utilized. The enzyme does not leach from the porous or non-porous support and the material retains enzymatic activity after prolonged storage. Differential biosensors are also disclosed.

Abstract: Methods and apparatus are disclosed for screening chemical samples to detect the presence of chemical warfare agents, chemical warfare agent precursors and degradation products formed therefrom. Particular applications include detection of the presence of a cholinesterase inhibitor derived from alkyloxy methylphosphonic acids, methylphosphonic acid, and methylphosphonofluoridic acid.

Abstract: A method of screening for a genetic predisposition to anticholinesterase exposure. The method includes the steps of obtaining a peripheral blood sample, and then analysing serum from the blood sample for BuChE levels and inhibitor-susceptibilities. The DNA of peripheral white blood cells from the blood sample is also screened for the presence of BuChE alleles thereby identifying patients who have a genetic predisposition to anticholinesterase exposure.

Abstract: A sensor for detecting the presence of at least one analyte includes at least one enzyme that is selected to either (i) catalyze a reaction of the analyte to chemically convert the analyte to a product compound or (ii) be inhibited by the analyte in the presence of a substrate compound. The sensor also includes at least one indicator compound selected to produce a measurable change of state as a result of the interaction of the analyte and the enzyme. Each of the enzyme and the indicator compound are incorporated within a single polymer.

Abstract: A method for assaying biological specimens for substances contained in the components of each specimen by the use of one or more kinds of calixarenes; and a reagent comprising one or more kinds of calixarenes. The method utilizes complexes formed by calixarenes and the components of biological specimens, and makes it possible to assay biological specimens for substances contained in the components of each specimen, for example, for cholesterol contained in high-density lipoprotein (HDL), without preliminary separation from the other components of the biological specimen. The method can be conducted by easy and simple operations and lessen measurement errors or problems caused by man, and permits continuous measurement with general-purpose automatic analyzing apparatuses and multi-channel measurement together with other test items.

Abstract: The present invention relates to a buckwheat starch syrup prepared by liquefying, saccharisfying, and proteolyzing starch from buckwheat flour, a method for preparing the buckwheat starch syrup, and various foods containing the same. The buckwheat starch syrup of the present invention contains various amino acids and minerals, as well as rutin which is effective in preventing arteriosclerosis, and hence it is healthy and excellent in nutritive balance. Thus, the buckwheat starch syrup of the present invention can be suitably used in various foods.

Abstract: The present invention relates to an enzyme sensor for measuring the concentration or activity of an analyte in a test fluid. The sensor has at least one enzyme layer comprising an immobilized enzyme for which the analyte is a substrate. The immobilized enzyme is obtained by formation of one or more covalent link(s), optionally by using a cross-linking agent, between the enzyme and at least one type of macromolecule in the presence of a competitive inhibitor for said enzyme. The present invention also relates to a membrane for an enzyme sensor. Furthermore, the invention relates to a method for stabilizing the enzymatic activity of an enzyme sensor.

Abstract: This invention relates to novel mammalian excitatory amino acid transporter proteins and genes encoding such proteins. The invention is directed towards the isolation, characterization and use of human excitatory amino acid transporter proteins for pharmacological screening of analogues, agonists, antagonists, inhibitors, modulators and facilitators of excitatory amino acid transport in a variety of tissues, particularly neuronal tissues. This invention provides isolated nucleic acid encoding a novel excitatory amino acid transporter subtype that is specifically expressed in retina. Also provided are recombinant expression constructs capable of expressing this novel transporter in transformed prokaryotic and eukaryotic cells, and also provides such transformed cell cultures producing the novel human transporter. Purified transporter protein and membranes comprising the transporter protein are also provided.

Abstract: The present invention relates to a method for the determination of cholesterol in low-density lipoprotein (LDL) in a sample containing LDL, which comprises eliminating cholesterol in high-density lipoprotein in the sample, subjecting the sample to a reaction utilizing the action of a cholesterol ester-hydrolyzing enzyme and the action of a cholesterol-oxidizing enzyme or of cholesterol oxidoreductase, and determining the amount of hydrogen peroxide or a reduced type coenzyme generated by the reaction.

Abstract: A method for determination of activity of a cholesterol oxidase comprises the following steps. A monomolecule film comprising a sterol and a phospholipid is formed on a surface of a cholesterol oxidase solution. Subsequently, a surface pressure of the monomolecule film is measured in order to find a rate of increase in the surface pressure of the monomolecule film where a magnitude of the activity of the cholesterol oxidase is defined by the rate of increase in the surface pressure.

Abstract: A new reagent and methods for measuring the concentration of (or detecting the presence of) an analyte in a sample. The reagent includes a phenazine-containing compound and an enzyme. The phenazine-containing compound must be of sufficient type to form a semiquinoid (the color indicator) by reaction involving the enzyme, analyte, and phenazine-containing compound. Importantly, the phenazine-containing compound must be in sufficient amount to correlate the concentration of semiquinoid to the concentration of analyte in the sample or to detect the presence of the analyte in the sample. The reagent may further include a buffer and a surfactant. The reagent may be incorporated into a film and may be provided in kit form.

Abstract: Enzyme activity is measured promptly with a high accuracy by introducing an enzyme, the activity of which is to be measured, into a column comprising a hollow tube packed with a filler comprising a support and a substrate that can be recognized by the enzyme, which is immobilized on the support, and measuring the amount of the obtained decomposition product of the substrate.

Abstract: Acetylcholinesterase and/or a receptor of acetylcholinesterase is immobilized on a solid support and stabilized by covering with a protective film of gelatin and/or albumin containing trehalose. The film is applied by covering the immobilized acetylcholinesterase and/or receptor of acetylcholinesterase with a layer of a gel-forming solution of gelatin or albumin in an evaporable solvent containing dissolved trehalose, and evaporating the solvent to leave the film. The film provides stability against dry heat, organic solvents, proteases and changes in pH. Other additives such as polyhydric alcohols, organic solvents, polymers and/or ionic and non-ionic components may be present to increase stabilization. A diagnostic kit or chromatography column may be formed containing the stabilized immobilized acetylcholinesterase and/or receptor of acetylcholinesterase.

Abstract: A method is provided for diagnosing of senile dementia of the Alzheimer type (Alzheimer's disease) by measuring acetylcholinesterase (AChE) activity in ocular fluids and determining if such AChE activity is elevated over that found in ocular fluids of patients who do not have Alzheimer's disease. A level of AChE activity in the ocular fluid of a patient less than 30% higher than the level of AChE activity in the ocular fluids of a significant number of age-matched controls signifies the absence of Alzheimer's disease. A level of AChE activity in the ocular fluid of a patient at least about 35% higher than the level of AChE activity in the ocular fluids of a significant number of age-matched controls signifies the presence of Alzheimer's disease.

Abstract: The invention is a non-invasive diagnostic test which is performed on the surface of the skin. This test indicates skin cholesterol levels which can provide information about the extent of aortic atherosclerosis. The invention also relates to reagents in the form of affino-enzymatic test compounds for use in the diagnostic test.

Abstract: Enzymatically clearable chemiluminescent 1,2-dioxetane compounds capable of producing light energy when decomposed, substantially stable at room temperature before a bond by which an enzymatically clearable labile substituent thereof is intentionally cleaved, are disclosed. These compounds can be represented by the formula: ##STR1## wherein: X and X.sup.1 each represent, individually, hydrogen, a hydroxyl group, a halo substituent, an unsubstituted lower alkyl group, a hydroxy (lower) alkyl group, a halo (lower) alkyl group, a phenyl group, a halophenyl group, an alkoxyphenyl group, a hydroxyalkoxy group, a cyano group or an amide group, with at least one of X and X.sup.1 being other than hydrogen; and R.sub.1 and R.sub.2, individually or together, represent an organic substituent that does not interfere with the production of light when the dioxetane compound is enzymatically cleaved and that satisfies the valence of the dioxetane compound's 4-carbon atom, with the provisos that if R.sub.1 and R.sub.

Abstract: The invention relates to polymeric compositions useful in analyte determination. The compositions contain a polymer, a reagent system for analyte determination, and an extender. The last component alleviates tackiness in the composition, and thus reduces damage in preparation of test apparatus. Mica is the particularly preferred extender.

Abstract: A colorimetric enzymic analytical test element comprises a support and a plurality of reaction zones incorporating a dried enzyme composition, dyestuff and reagent adapted to provide a substantial dosage independent colorimetric display when the concentration of an analyte applied to the elements exceeds a predetermined value.

Abstract: A method of inhibiting the function of .beta.-protein, particularly enzymatic activity, such as esterase (cholinesterase) or proteinase activity, is to contact .beta.-protein with a compound which inhibits such enzymatic activity. Examples of such inhibitors are para-amidinophenylmethanesulfonyl fluoride and Ebelactone A, which inhibit the esterase activity of amyloid precursor protein to a greater extent than the esterase activity of acetylcholinesterase.

Abstract: A non-radioactive, spectrophotometric, microtiter plate assay for human cystolic phospholipase A.sub.2 (cPLA.sub.2) is described. The assay utilizes a novel synthetic thiol-phospholipid analog as a substrate. In one embodiment, the substrate is a phosphatidylcholine derivative with an arachidonoylthioester in the sn-2 position and an alkenyl-ether or alkenyl-ether in the sn-1 position. The alkyl-ether and the alkenyl-ether in the sn-1 position of the substrate ensures that the assay will only measure cPLA.sub.2 activity and will not be complicated by metabolism of the lysophospholipid product by the enzyme's and lysophospholypase activity.

Abstract: A method is provided for measuring the net HDL cholesterol in the blood. The LDL and VLDL moieties are precipitated out and the remaining cholesterol content of the supernatant is measured. The free cholesterol content of the supernatant is separately measured and substracted from the total to obtain net HDL cholesterol. This value serves as a useful indicator for diagnosing vascular disease. A diet supplement and method for raising serum HDL is provided.

Abstract: A dye couple, comprising 3-methyl-2-benzothiazolinone hydrazone (MBTH) and 8-anilino-l-naphthalenesulfonate (ANS), is used as an indicator in a reaction cascade producing a strong oxidizing agent, such as hydrogen peroxide or other peroxides or perborates. The strong oxidizing agent reacts with the dye couple to produce a blue dye stuff. The MBTH-ANS dye couple exhibits strong and flat spectral absorption at the region of about 600 to 650 nm. This region is free of blood color interference, which enables one to measure glucose and other analytes that react with an oxidase enzyme to produce the strong oxidizing agent, through the use of LED optics, accurately without much optic calibration. Further, the MBTH and ANS are very soluble in aqueous solution, yet become insoluble upon oxidative coupling. The poor solubility minimizes dye fading, thus providing a stable endpoint.

Abstract: The invention refers to a method for determining the relative amounts of all cholesterol-containing lipoproteins in body fluids comprising electrophoretically separating the lipoproteins of an aliquot of body fluid on a thin layer carrier matrix, incubating the carrier matrix, containing the separated lipoproteins with cholesterol esterase and cholesterol dehydrogenase, forming a provable complex, and determining the relative amounts of the different lipoprotein classes2. The new method makes it possible to simultaneously determine HDL-, LDL-, VLDL- and LP (X)-cholesterol in body fluids with a high accuracy even at small concentrations. The thin layer matrices obtained electrophoretically, are very easy to handle and to record.

Abstract: A substrate or an enzymatic activity in a body fluid can be measured accurately without influences of interfering substances such as bilirubin by reacting an oxidase corresponding to an analyte with the analyte or an oxidase corresponding to a substance produced by enzymatic reaction with the substance in a measuring system containing one or more cationic and/or amphoteric surfactants, followed by optical measurement of hydrogen peroxide produced by the reaction.

Abstract: The subject invention provides a method for analyzing the metabolic activity in cells by improving the retention of a detectable reporter molecule only in intact cells where a particular enzyme is present. In particular, improved retention results from a two part process involving conjugation of haloalkyl-substituted derivatives of a reporter molecule with intracellular cysteine-containing peptides while unblocking the reporter molecule. The method for analyzing metabolic activity of cells involves the use of a substrate having the formXR-REPORTER-BLOCKwherein -BLOCK is a group selected to be removable by action of a specific analyte, to give REPORTER spectral properties different from those of the substrate,-REPORTER- is a molecule that, when no longer bound to BLOCK by a BLOCK-REPORTER bond, has spectral properities different from those of the substrate, andXR-- is a haloalkyl moiety that can covalently react with an intracellular thiol (Z--S--H) to form a thioether conjugate (Z--S--R--).

Abstract: A dry analytical element for the determination of serum cholinesterase (CHE) activity is disclosed. The element analyses undiluted body fluids and employs butyrylthiocholine as the substrate for CHE. Butyrylthiocholine is hydrolyzed by serum cholinesterase and liberates butyric acid and thiocholine. The thiocholine liberated then reduces ferricyanide to ferrocyanide and the rate of change is measured by reflectance densitometry.

Abstract: There is provided a simple method to identify cation channels expressed in cultured cells and to screen chemical agents for their use as agonists or antagonists to such channels. In addition, the invention assay method also provides rapid means to identify cultured cell lines which express functional ion channels. The invention assay method can readily be adapted for the low cost, automated screening of potential drug materials.

Abstract: A method is provided for the screening of senile dementia of the Alzheimer type (Alzheimer's disease) by testing for an anomalous molecular form of acetylcholinesterase in cerebrospinal fluid of a patient.

Abstract: This invention relates to a process for the recovery of a substantially insoluble, radiation imageable polyacetylene dispersion in aqueous binder which comprises contacting the dispersion with a proteolylic enzyme in an amount sufficient to decompose the binder, at a pH of from about 3 to about 9 and a temperature of between about 20.degree. C. and about 70.degree. C. and separating polyacetylene solids from the resulting liquid mixture, and which solids can be solubilized and recrystallized for further use.

Abstract: Reagent for analysis of triglycerides contained in blood serum is provided, which comprises lipases and monoglyceride lipases capable of acting on monoglycerides having substrate specificity and capable of catalyzing the following enzymatic reaction: monoglyceride+H.sub.2 O.fwdarw.glycerol+fatty acids. The glycerol or fatty acids are measured to learn an amount of the triglycerides or fatty acid by any known analytical method.

Abstract: An assay with high sensitivity for activity of lecithin-cholesterol acyltransferase in blood for functional analysis of liver, by bringing the blood into contact with lecithin and free cholesterol until lysolecithin and cholesterol ester are produced, allowing the lysolecithin produced to react with lysophospholipase and glycerophosphocholine phosphodiesterase and assaying glycerol-3-phosphate produced simultaneously or successively in the reaction by means of an enzymatic cycling reaction in which glycerol-3-phosphate, dihydroxyacetone-3-phosphate, nicotinamide adenine dinucleotide (NAD), reduced NAD, O.sub.2, H.sub.2 O.sub.2, glycerophosphate oxidase and glycerophosphate dehydrogenase take part.

Abstract: A method for producing a binding assay device composed of antigens on a cellulose nitrate, cellulose nitrate/acetate or similar solid phase is described. The method involves applying to a solid phase a small amount of an allergen composition, or a pretreated allergen composition, containing a certain concentration of allergen and drying the solution. The device is used by contacting a patient test sample to the immobilized allergen and determining whether or not the test sample contains IgE antibodies for the allergen.

Abstract: Compound labelled by the acetyl cholinesterase of Electrophorus electricus, its preparation process and its use in enzymoimmunology.This compound is constituted by a molecule chosen from among the antigens, haptens and antibodies, bonded by a covalent bond to an enzyme formed by the acetyl cholinesterase of Electrophorus electricus (electric eel).For example, the molecule is the substance P or a prostaglandin and the compound can be used for the enzymoimmunological determination of these molecules.

Abstract: An electrical biosensor for analyte determination is prepared by polymerization of a mixture of a biological receptor capable of binding an analyte in a sample, a protein and a polymerizing agent such as glutaraldehyde to form a polymeric film on a transducer. The mixture preferably contains a stabilizer selected from lipids, detergents and antioxidents. The receptor may be an acetylcholine receptor and the analyte, acetylcholine. A preferred stabilizer is a combination of phosphatidyl choline and octyphenoxypolyethoxyethanol. In carrying out a determination, analyte in a sample binds to the receptor causing a change in an electrical characteristic of the film which is indicative of the presence of the analyte. The biosensor may contain a second polymeric film that is free of the receptor and which serves as a control.

Abstract: A novel compound, 6-acetoxymethyl-2-naphthoylcholine halide, is very stable to nonenzymatic hydrolysis and react specifically with cholinesterase in serum. A UV method for determining cholinesterase activity in serum which uses the novel compound as a substrate permits very accurate and highly reproducible determination of cholinesterase activity in serum, and therefor is very useful for clinical examination.

Abstract: A method for assay for an unknown enzyme suspected to be present in a liquid includes signal amplification by use of a second enzyme and a blocked modulator for the second enzyme. Unknown enzyme in the liquid removes a blocking group from the blocked modulator. The resulting modulator activates or inhibits the second enzyme which catalyzes an indicator reaction in which a substrate is converted to a product. The presence or absence of the unknown enzyme in the liquid is indicated by a signal, such as a color change or a rate of color change, associated with the indicator reaction. The concentration of the enzyme in the sample may be determined by the measurement of the signal. The invention includes a kit of materials useful for performing the method of the invention. The method involves the hydrolyzing of a blocked fluoroketone inhibitor to facilitate the analytical method.

Abstract: An analytical element to measure a specific component in a fluid samples comprising support, a layer containing a reagent provided the support and a spreading layer provided on above the reagent containing layer. In the spreading layer, an emzyme necessary for the reaction to produce a product capable of being detected with said reagent from the specific component is contained. The enzyme is protected from deterioration of activity during a manufacturing and preservation of the analytical element by means of the enzyme is included in the spread layer as a dispersion mixture with a protein and/or polypeptide. An accurate analytical result is stably obtained by the analytical element.

Abstract: This invention relates to a method for determination of cholinesterase activity, characterized by using, as a substrate, a choline derivative represented by the general formula (I): ##STR1## wherein X is a halogen atom; Y.sub.1 is a hydroxyl group as a substituent in the 2- or 5-position; and Y.sub.2 is a hydroxyl group as a substituent in the 3-position.The determination method of this invention permits easy and simple determination of cholinesterase activity, and is very useful as a determination method for clinical examinations for the purpose of determining cholinesterase in serum.

Abstract: A method for enzyme immunoassay for a ligand suspected to be present in a liquid sample includes signal amplification by use of at least two hydrolases and a blocked fluoroketone for one of the hydrolases. Ligand present in the liquid binds to an antiligand and a hydrolase-labeled tracer. The resulting bound fraction is separated and the hydrolase in the tracer removes the blocking group from the blocked fluoroketone. The fluoroketone activates or inhibits a second hydrolase which catalyzes the conversion of a substrate to a product. The presence or absence of the ligand in the liquid is indicated by a signal, such as a color change or a rate of color change, associated with the product. The invention includes a new class of hydrolase inhibitors and blocked fluoroketones and a kit of materials useful for performing the method of the invention.

Abstract: In a method for determining cholinesterase (hereinafter referred to as ChE) activity, the improvement comprising by using, as a substrate, a protocatechuoylcholine derivative represented by the general formula (I), ##STR1## (wherein X is a halogen atom). The method for determining ChE activity according to the present invention is free from defects of the conventional methods, has many advantages and characteristics, permits accurate and simple determination of ChE activity, and can sufficiently contribute to determination of ChE activity in daily clinical examinations.

Abstract: A cholinesterase-assaying reagent containing acetylcholine, a thermostable acetate kinase, and adenosine triphosphate is disclosed. This reagent makes it possible to assay cholinesterase, whose activity is clinically important, with good reproducibility and high accuracy.

Abstract: A method is provided for the integration of a low-volume liquid flow and ing system and a portable optical waveguide-based fluorescence detector for the chemical analysis of reagents in fluorescence-based reactions. The method is particularly applicable to the detection of enzyme inhibitors, modifiers, or ligands in cases where a fluorescent enzyme substrate or product exists. In a preferred embodiment, the presence and concentration of acetylcholinesterase inhibitors, such as chemical warfare nerve agents or certain insecticides, is determined by mixing aqueous samples with a dilute solution of n-methyl indoxyl acetate, and monitoring the formation of a fluorescent product (n-methyl indoxyl). The presence of an acetylcholinesterase inhibitor reduces the amount of fluorescent product formed in a given time period.