title: Stabilization of penicillinase-hapten conjugate for enzyme immunoassay.
abstract: The influence of various additives, such as organic solvents, polyhydric alcohols, salts, polymers, and cross-linker, on the stability and storage ability of penicillinase-morphine conjugate was studied in liquid and solid (freeze dried) states. The results of these experiments showed that using low concentrations of CaCl2 (0.1-0.2%) could stabilize enzyme activity in both states for more than seven months. The immunoreactivity of antigen toward the antibody did not change significantly. However, a cross-linker such as glutaraldehyde and various additives such as dimethylsulfoxide, glycerol, polyethylene glycol, gelatin, dextran, ammonium sulfate, lactose, and sucrose did not have any effect on stability. In addition, it was found that the presence of lactose and sucrose in the lyophilization procedure gives a significant amount of protection to the enzyme, which could last for a period of seven months and preserve almost 95% of the enzyme activity, as well as immunoreactivity of the tracer molecule.
authors.affiliation: Tarbiat-Modarres University, School of Medical Sciences, Department of Biochemistry, Tehran, Iran.
authors.forename: K
authors.initials: K
authors.lastname: Omidfar
authors.forename: Mohammad J
authors.initials: MJ
authors.lastname: Rasaee
authors.forename: Ali B
authors.initials: AB
authors.lastname: Zaraee
authors.forename: M Pour
authors.initials: MP
authors.lastname: Amir
authors.forename: F
authors.initials: F
authors.lastname: Rahbarizadeh
mesh_terms: D002122:Calcium Chloride / Q000494:pharmacology; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D006241:Haptens / Q000276:immunology; D018796:Immunoconjugates / Q000187:drug effects; D007124:Immunoenzyme Techniques / Q000592:standards*; D009020:Morphine / Q000276:immunology; D010405:Penicillinase; D011310:Preservatives, Pharmaceutical / Q000494:pharmacology; D013696:Temperature
chemical_list: D003432:Cross-Linking Reagents; D006241:Haptens; D018796:Immunoconjugates; D011310:Preservatives, Pharmaceutical; D009020:Morphine; D010405:Penicillinase; D002122:Calcium Chloride