Verification of the Storage Stability of Fecal Hemoglobin in Stool Sampling Bottle Using Improved Buffer - A Pilot...

Area of Science:

• Clinical Chemistry
• Biochemistry
• Colorectal Cancer Screening

Background:

• Fecal immunochemical testing (FIT) accuracy is influenced by sample storage conditions.
• Conventional stool collection buffers may compromise analyte stability, impacting test results.

Purpose of the Study:

• To compare an improved stool collection buffer with a conventional one.
• To evaluate stability of fecal hemoglobin (Hb), transferrin (Tf), and calprotectin (FC) under various conditions.
• To assess the improved buffer's suitability for postal FIT-based colorectal cancer screening.

Main Methods:

• 130 patient stool samples were analyzed using both buffer types.
• Fecal Hb, Tf, and FC levels were measured.
• Correlation and high-temperature stability (37°C for 1 week) were assessed.

Main Results:

• The improved buffer showed strong correlation (r ≥ 0.95) for all three markers compared to the conventional buffer.
• Significantly higher residual reactivity for Hb was observed with the improved buffer (p < 0.01).
• Tf stability remained high (>90%) in both buffers; FC stability was better preserved in the improved buffer under prolonged high-temperature exposure.

Conclusions:

• The improved buffer offers superior Hb stability at high temperatures and concentrations.
• It effectively preserves Tf and FC, addressing limitations of conventional buffers.
• This buffer shows potential for enhancing postal stool collection in FIT-based colorectal cancer screening programs.