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Protein labeling calculator

Calculate the dye amount and expected degree of labeling (DOL) for NHS ester fluorescent dye conjugation

Input parameters

Reference: Cy5-NHS ≈ 792, FITC ≈ 389

Typically 10 mM in DMSO

Recommended 5–20×

Results

Fill in the parameters and click "Calculate" to see results

Calculation principles

Protein amount (μmol) = concentration (mg/mL) × volume (μL) / MW (Da)

Dye required (μmol) = protein amount (μmol) × molar ratio

Dye stock volume (μL) = dye required (μmol) / stock concentration (mM) × 1000

Note: actual DOL is affected by buffer pH, reaction time, protein activity and other factors. Use the UV-Vis measured value as the definitive result.

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