ProteinConcentrationUVQualityChecker

Protein Concentration UV Quality Checker — Control of Protein Concentration and Purity (UV)

ℹ️  Utility checks critical parameters of protein analysis by UV spectrophotometry:
   • Calculated concentration: within ±10% of expected
   • A260/A280 Ratio: ≤0.7 (indicator of no DNA/RNA)
   • Absorbance A280: in linear range (0.1–1.5 AU)

⚠️  CRITICAL: High A260/A280 ratio (>0.8) indicates significant nucleic acid contamination!
   Concentration will be overestimated if formula is not corrected.

Usage:
 ProteinConcentrationUVQualityChecker.exe                            → demo mode (console output)
 ProteinConcentrationUVQualityChecker.exe input.csv output.json      → evaluate your data

Input format:
BatchNumber,AbsorbanceAt280,AbsorbanceAt260,ExtinctionCoefficient,PathLengthCm,ExpectedConcentrationMgMl

Example:
 PROT-UV-2026-001,0.850,0.450,1.4,1.0,0.60

— WHY IS THIS NEEDED?
Rapid, non-destructive protein concentration determination is a routine task in biopharma.
• Based on light absorption by aromatic amino acids (Tryptophan, Tyrosine) at 280 nm.
• Beer-Lambert law allows accurate concentration calculation with known extinction coefficient.
• A260/A280 ratio serves as a quick purity test for DNA/RNA traces.
• Automation eliminates manual coefficient entry errors.

⚠️  CRITICAL:
• Extinction coefficient is specific to each protein (depends on sequence).
• Buffer components (e.g., imidazole, DTT) may absorb at 280 nm and distort result.
• Micro-volume instruments (NanoDrop) require thorough pedestal cleaning.
• For high concentrations (>2-3 mg/mL), non-linearity may occur due to aggregation.

Key features:
• Automatic concentration calculation (mg/mL).
• Purity assessment by spectral ratio.
• Measurement validity check (linear range).

Critical parameters:
• Concentration Accuracy: +/- 10% of Expected
• A260/A280 Ratio: <= 0.7
• A280 Linearity: 0.1 - 1.5 AU

💡 Usage tips:
1. Always use the same buffer for blank as for sample.
2. If A260/A280 is high, consider purification by precipitation or column.
3. For proteins without tryptophan, method is inapplicable (use BCA or Bradford).
4. Check for air bubbles in cuvette/pedestal.
5. Regularly calibrate instrument using BSA standard solutions.

⚠️ Note: A280 method measures only proteins containing aromatic amino acids. Peptides or small proteins may have very low absorption, reducing method sensitivity.