Dried blood spot test estimation of urea

Area of Science:

• Clinical Chemistry
• Biomedical Diagnostics

Background:

• Accurate urea level measurement is vital for diagnosing kidney function and metabolic disorders.
• Traditional blood sample analysis requires immediate processing, posing logistical challenges.

Purpose of the Study:

• To evaluate the feasibility and accuracy of analyzing urea in dried serum and whole blood samples on filter paper.
• To determine the suitability of this method for neonatal capillary blood samples.

Main Methods:

• Investigated urea analysis in serum and whole blood dried onto filter paper.
• Assessed the impact of sample volume and application volume on results.
• Emphasized calibration using a serum-based standard due to potential matrix effects.

Main Results:

• Sample volume and applied volume were non-critical for consistent disc punching.
• Achieved a coefficient of variation of approximately 6% across a wide urea concentration range.
• Demonstrated good correlation with a standard laboratory procedure.

Conclusions:

• Dried filter paper offers a stable and reliable matrix for urea analysis.
• The method is particularly applicable to neonatal capillary samples, simplifying collection and transport.
• Serum-based calibration is essential for accurate quantification due to matrix effects.