Liposome immunoassay (LIA) for gentamicin using phospholipase C

Area of Science:

• Biochemistry
• Analytical Chemistry
• Immunology

Background:

• Traditional immunoassays often rely on complement, which can be complex to standardize.
• Developing sensitive and rapid detection methods for gentamicin and similar molecules is crucial for therapeutic drug monitoring and diagnostics.

Purpose of the Study:

• To develop a simple and sensitive liposome immunoassay for gentamicin detection.
• To utilize phospholipase C as a cytolytic agent in the immunoassay, replacing complement.

Main Methods:

• Liposomes entrapping calcein were prepared using dimyristoylphosphatidylcholine and cholesterol.
• Gentamicin was covalently coupled to phospholipase C to create a conjugate.
• Liposome lysis was induced by the gentamicin-phospholipase C conjugate, releasing calcein.
• The assay's sensitivity was determined using a standard calibration curve.

Main Results:

• The developed liposome immunoassay demonstrated sensitivity for gentamicin detection.
• The standard calibration curve was linear over a concentration range of approximately 2.5 pg/ml to 2.5 ng/ml.
• The lytic activity of the conjugate was inhibited by gentamicin antiserum, confirming assay specificity.

Conclusions:

• A simple, rapid, and sensitive liposome immunoassay for gentamicin has been successfully developed.
• The assay utilizes phospholipase C, offering an alternative to complement-based methods.
• This method shows potential for determining concentrations of antigens, drugs, and endogenous substances.