Wako Pure Chemical Industries, Inc.

Masaaki Kida

Kazuhisa Kubotsu

Yoshitsugu Sakata

Sachiko Yamamoto

Toyoharu Mukai

Tsutomu Iwata

Kazunari Hashidume

Shuji Matuura

Minoru Fujita

Kazunisa Kubotsu

Sachiko Goto

Isako Kitabata

A reagent composition comprising (a) liposomes encapsulating a marker therein, immobilizing a hapten on liposome membranes and having a size in the range of 100 to 500 nm in terms of mean particle size plus twice the standard derivation, and (b) an antibody to the hapten is effective for measuring human complement activity easily and precisely with excellent storage stability.

Process for measuring complement activity and reagent used therefor

Complement immunoassay using liposomes is improved by pretreatment of a sample solution before determination of analyte comprising acidifying or alkalinizing the sample solution, followed by changing the pH to about neutral so as to remove influences caused by interfering substances present in the sample.

Immunoassay using liposomes

Membranes of liposomes fixing biotin on membrane surfaces thereof can be lysed by a mixed agent comprising a surfactant and avidin. This mechanism can be applied to immunoassay for determining an analyte, e.g. antigen or antibody, wherein liposomes encapsulating a marker and fixing biotin on membrane surfaces thereof are lysed depending on hindrance of an avidin-biotin binding reaction by a specific reaction caused by the analyte.

Process for quantitatively lysing liposomes and a process for

A combination of reagents including (i) a first liquid containing (a) first microcapsules having an analyte immobilized on surfaces thereof and containing a marker therein and (b) microcapsules encapsulating an antibody and having different capsule walls from said first analyte immobilized microcapsules with respect to susceptibility to a capsule wall lysin, and (ii) a second liquid containing complement is suitable for immunoassay based on complement-dependent immune lysis of microcapsules.

Immunoassay process and liquid reagents used therefor

Urea derivatives of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are independently a 4-disubstituted aminoaryl group or the like, and R.sup.3 is a carboxyalkyl group or the like, is soluble in water and effective as a color producing reagent for determining hydrogen peroxide or the like or the activity of peroxidase.

Urea derivatives

Novel functionallized liposomes containing a high-molecular-weight amphiphilic compound such as LPS etc. as one of matrix material have a very high encapsulation efficiency and readily undergo lysis. Moreover, antigen, antibody, etc. can be immobilized on the liposomes efficiently with a sufficient binding rate by using the amphiphilic compound as a spacer.

Growing community of inventors

Amagasaki, Japan

Masaaki Kida