Advantage is taken of macrolide antibiotics' complexation with free cholesterol to yield fluorescent complexes to determine the levels of free cholesterol, total cholesterol, or lecithin: cholesterol acyl transferase (LCAT) in serum or plasma or fractions thereof.

Advantage is taken of macrolide antibiotics' complexation with free cholesterol to yield fluorescent complexes to determine the levels of free cholesterol, total cholesterol, or lecithin: cholesterol acyl transferase (LCAT) in serum or plasma or fractions thereof.

A method of lipid assay characterized by assaying the lipids contained in a blood component in the presence of an organic silicon compound. The method can cause specific conditions for direct methods while satisfying requirements such as no influence on precision of assay, no burden on assay apparatus, and easy availability.

A method of lipid assay characterized by assaying the lipids contained in a blood component in the presence of an organic silicon compound. The method can cause specific conditions for direct methods while satisfying requirements such as no influence on precision of assay, no burden on assay apparatus, and easy availability.

The present invention provides a co-culture system and method for assessing cellular cholesterol (Choi) efflux and uptake in vitro. The co-culture system mimics in vivo Choi efflux and uptake in the context of mammalian physiology. The methods and systems provided can be used in some embodiments to evaluate the effect of a pharmacological agent on cellular Choi efflux and uptake or for diagnostic purposes.

The present invention provides a co-culture system and method for assessing cellular cholesterol (Choi) efflux and uptake in vitro. The co-culture system mimics in vivo Choi efflux and uptake in the context of mammalian physiology. The methods and systems provided can be used in some embodiments to evaluate the effect of a pharmacological agent on cellular Choi efflux and uptake or for diagnostic purposes.

A 2-substituted benzothiazolyl-3-substituted phenyl-5-substituted sulfonated phenyl-2H-tetrazolium salt represented by the following Formula (1):

##STR00001##

wherein, R.sup.1 can be a hydrogen atom, a hydroxyl group, a methoxy group, and an ethoxy group; R.sup.2 can be a nitro group, OR.sup.4, and a carboxyl group; R.sup.3 is a hydrogen atom, a methyl group, or an ethyl group, while at least one is a methyl group or an ethyl group; R.sup.4 is a methyl group or an ethyl group; m is 1 or 2; n is an integer from 0 to 2; p is 0 or 1; n+p is 1 or greater; q is 1 or 2; when q is 2, the OR.sup.3's are disposed adjacently to each other and may form a ring; and X is a hydrogen atom or an alkali metal atom.

A method of testing a liquid sample for the presence of an analyte, the method comprising the steps of: forming a mixture by contacting the sample with a composition comprising an oxidase for formation of hydrogen peroxide from the analyte, a fluorescent indicator precursor capable of forming a fluorescent indicator in the presence of an oxygen radical and an iron compound wherein the iron compound is dissolved in the mixture; irradiating the mixture; and measuring fluorescence from the fluorescent indicator. The method may be carried out using a device in which the mixture in a channel or chamber (101) of a microfluidic device is irradiated by light from light source (103) and emission from the fluorescent indicator is detected by photodetector (105).

A method that enables quantification of cholesterol in high-density lipoprotein 3 (HDL3) in a test sample without requiring a laborious operation is disclosed. The method for quantifying cholesterol in HDL3 comprises: Step 1 wherein phospholipase and/or sphingomyelinase is/are allowed to act on a test sample to transfer cholesterol to the outside of the reaction system; and Step 2 wherein cholesterol remaining in the reaction system is quantified. The method enables specific quantification of HDL3 cholesterol in a test sample using an automatic analyzer without requirement of a laborious operation such as ultracentrifugation or pretreatment. Further, quantification of the HDL2 cholesterol level can also be carried out by subtracting the HDL3 cholesterol level from the total HDL cholesterol level obtained by a conventional method for quantifying the total HDL cholesterol in a test sample.

A method that enables quantification of cholesterol in high-density lipoprotein 3 (HDL3) in a test sample without requiring a laborious operation is disclosed. The method for quantifying cholesterol in HDL3 comprises: Step 1 wherein phospholipase and/or sphingomyelinase is/are allowed to act on a test sample to transfer cholesterol to the outside of the reaction system; and Step 2 wherein cholesterol remaining in the reaction system is quantified. The method enables specific quantification of HDL3 cholesterol in a test sample using an automatic analyzer without requirement of a laborious operation such as ultracentrifugation or pretreatment. Further, quantification of the HDL2 cholesterol level can also be carried out by subtracting the HDL3 cholesterol level from the total HDL cholesterol level obtained by a conventional method for quantifying the total HDL cholesterol in a test sample.