Pre-Weighed Biotinylation Reagents

Detection and purification of proteins are the core methods in life science experiments. The biotin-avidin interaction is often used to detect or purify proteins because of its high binding affinity. 1 and 2 are biotinylation reagents containing both a linker and an N-hydroxysuccinimidyl ester (NHS) moiety and are pre-weighed in suitable amounts for protein biotinylation. They can biotinylate proteins by reacting with amino groups (-NH₂) of proteins and by forming amide bonds at pH between 7 and 9. Below is the direction for use.

Preparation:
It is recommended to prepare a 10 mM biotinylation solution. In order to efficiently biotinylate a sample, biotinylation solution should be used at a 15-fold molar excess over the amount of amine-containing protein. Here shows the calculation of the 10 mM biotinylation solution amount.
Calculate Example: A μL of 10 mM biotinlation solution for biotinylation 2 mg IgG (150,000 M.W.)

2 [mg IgG] × 10^-3 [g/mg] × 1/150,000 [mol/g] × 15 [fold]
= A [μL of 10 mM biotinylation solution] × 10^-6 [L/μL] × 10 [mmol/L] × 10^-3 [mol/mmol]

A = 20 [μL of 10 mM biotinylation solution]

Direction for Use

1. Bring 1, 2 to room temperature and dissolve 2 mg of 1 in 350 μL of DMSO or DMF, or 2 mg of 2 in 400 μL of PBS to prepare a 10 mM biotinylation solution.
2. Dissolve the sample (1-10 mg/mL) in an appropriate buffer with pH between 7 and 9 such as PBS. Do not use buffers including amines (such as Tris).
3. Add A μL (calculated above) of 10 mM biotinylation solution to the sample solution and incubate the mixed solution for 30 min at room temperature.
4. Remove unreacted and hydrolyzed reagent by a desalting column or dialysis.