What is the reference range for total protein in serum?

• A. 6.5-8.3 g/dL
• B. 4.0-6.0 g/dL
• C. 7.0-9.0 g/dL
• D. 5.0-7.0 g/dL

Answer: (A)

Total protein in serum is the sum of albumin and all globulin fractions, so it reflects the overall protein content of the blood. The reference range most commonly used for a healthy adult is about 6.5–8.3 g/dL (65–83 g/L). This range represents the typical combined concentration of the major protein components in serum. Values outside this range can point to different clinical issues: dehydration can raise the level by concentrating the plasma, while decreased total protein may indicate liver disease, nephrotic syndrome, or malnutrition. Conversely, chronic inflammation or conditions with increased globulins can push the total higher. Among the given options, 6.5–8.3 g/dL best matches the standard reference interval.