Which of the following options is least likely to interfere with blood chemistry test results?

• A. Postprandial serum
• B. Fasting serum
• C. Icteric serum
• D. Hemolyzed serum

Answer: (B)

When measuring blood chemistry, anything that changes the serum’s clarity, color, or composition can skew results. Fasting serum minimizes these interferences because it reduces lipids from recently ingested meals, leading to a clearer serum and more stable baseline analyte levels. That makes fasting serum less likely to distort photometric readings or enzyme/electrolyte measurements than a sample taken after eating.

Postprandial serum often becomes lipemic, appearing milky due to elevated triglycerides and chylomicrons. This turbidity can interfere with many colorimetric assays by scattering light or altering the apparent concentration of analytes, leading to inaccurate results.

Icteric serum has excess bilirubin, which gives a yellow color and absorbs light at wavelengths used by many tests. This color interference can falsely shift results for various chemistry assays.

Hemolyzed serum results from red blood cell rupture, releasing hemoglobin and intracellular components like potassium and certain enzymes. This can artificially raise or lower results and disrupt many measurements.

Thus, fasting serum is the least likely to interfere with blood chemistry test results.