Guidelines (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs).
Calculations
:
For best results, use ≥ 12-fold molar excess of biotin for a 10 mg/mL protein solution or ≥ 20-fold molar excess of biotin for a 2 mg/mL protein solution.
1.Calculate millimoles of biotin reagent to add to the reaction for a 20-fold molar excess:
mL protein × (mg protein/mL protein) × (mmoL protein/mg protein) × (20 mmoL protein/mmoL protein) = mmoL Biotin.
* 20 = Recommended molar fold excess of biotin for 2 mg/ml protein sample
2. Calculate microliters of 10 mM biotin reagent solution (prepared in Step B.3) to add to the reaction:
mmoL Biotin × (1000000 μL/L) × (L/ 10 mmoL) =μL Biotin
Biotin Labeling Reaction
:
1. Dissolve 1-10 mg protein in 0.5-2.0 mL PBS according to the calculation made in Calculations.
2. Before use, prepare a 10 mM solution of the biotin reagent in an organic solvent such as DMSO.
3. Add the appropriate volume (μL) of 10 mM biotin reagent solution to the protein solution.
4. Incubate reaction on ice for two hours or at room temperature for 30 minutes.
5. To tests the labeled protein by ELISA or Western blot.