The Quantitative Detection of Cystatin-C in Patient Samples Using a Colorimetric Lateral Flow Immunoassay

Area of Science:

• Biomedical Diagnostics
• Immunoassay Technology
• Clinical Chemistry

Background:

• Cystatin-C is a biomarker for kidney function.
• Accurate and rapid measurement of Cystatin-C is crucial for diagnosing renal failure.
• Existing methods may lack point-of-care convenience.

Purpose of the Study:

• To develop a rapid, quantitative lateral flow immunoassay (LFA) for Cystatin-C detection.
• To evaluate the analytical performance and stability of the developed Cystatin-C-LFA device.
• To assess the suitability of the device as a point-of-care diagnostic tool.

Main Methods:

• Development of a colloidal gold-based lateral flow immunoassay.
• Quantitative detection of Cystatin-C in serum and whole blood samples.
• Validation against a standard nephelometric immunoassay.
• Assessment of assay time, quantification range, limit of detection, precision, sensitivity, interference, and stability.

Main Results:

• The Cystatin-C-LFA provides quantitative detection within 15 minutes.
• The assay has a quantification range of 0.5–7.5 µg/mL and a lower limit of detection of 0.18 µg/mL.
• Results showed a strong linear correlation (adjusted r² = 0.95) with a standard method.
• The device demonstrated satisfactory analytical performance and stability over 30 days at 50 °C.

Conclusions:

• The developed Cystatin-C-LFA is a rapid and accurate point-of-care diagnostic tool.
• The device shows potential for precise Cystatin-C quantification, especially in patients with renal failure.
• Its stability indicates a long shelf life, enhancing its utility in clinical settings.