Multilayer film elements for clinical analysis: applications to representative chemical determinations

Area of Science:

• Clinical Chemistry
• Analytical Chemistry
• Biomedical Engineering

Background:

• Dry multilayer analytical elements provide a versatile platform for biochemical assays.
• Modifications in chemical procedures and element configurations enable the simultaneous analysis of various blood components.

Purpose of the Study:

• To demonstrate the adaptability of dry multilayer analytical elements for assaying serum urea nitrogen, amylase, bilirubin, and triglycerides.
• To detail the specific enzymatic and chemical reactions employed for each analyte within the multilayer element.

Main Methods:

• Serum urea nitrogen is assayed via urease-catalyzed urea hydrolysis, with ammonia diffusion to an indicator layer.
• Amylase activity is determined by measuring the absorbance increase at 540 nm resulting from dyed-starch substrate hydrolysis.
• Bilirubin is quantified by direct reading at 460 nm following complexation with a cationic polymer.
• Triglycerides are analyzed through enzymatic hydrolysis, phosphorylation, and subsequent oxidation, producing a colorimetric response.

Main Results:

• The described methods allow for the determination of serum urea nitrogen, amylase activity, total bilirubin (1-500 mg/liter), and triglycerides.
• Each assay utilizes specific layers within the dry element for analyte separation, reaction, and detection.

Conclusions:

• Dry multilayer analytical elements are effective for the simultaneous, quantitative assay of diverse blood components.
• The adaptable design facilitates customized chemical assays for various clinical diagnostic needs.