protocol_408.txt

Mucin biotinylation - NHS-biotin reagent
Calculate how much NHS-Biotin that is needed for biotinylation of the desired amount of mucin (assumed to have Mw 500 000 Da) and the molar ratio of biotin:mucin should be 1:2000.
Prepare Phosphate Buffered Saline (PBS) with pH 7.4.
Dissolve mucin in PBS to a concentration of 2mg/ml.
Take out the NHS-Biotin reagent and equilibrate it in room temperature before opening the vial.
Dissolve NHS-Biotin in dimethylsulfoxide (DMSO) to a concentration of 10 mM.
Add the pre-calculated volume of biotin reagent to the protein solution and incubate at 4 °C for 4 hours.
To remove unbound biotin, exchange the buffer for water by overnight dialysis.
Transfer the solution to another tube, freeze and freeze-dry.