With a Nanodrop you are only going to measure total protein (or more specifically total aromatic amino acid concentration). So if your antibodies are pure and free from any other proteins, then you can determine their concentration using a Nanodrop. But if there is serum, or carrier protein or similar in the solution, then the background might be too high to measure the antibody concentration.

Yes, you can use a Nnodrop to measure the concentration of your monoclonal antibody (mAb). Measure at 280 nm, using the antibody's extinction coefficient (typically ~1.4 for 1 mg/mL IgG if not known exactly).

Michael J. Benedik each time I want to measure the concentration, the mAb has been purified, so I assume it's pure.

Shahina Akter , Is there a way to calculate this extinction coefficient ? I'll work with pembrolizumab and nivolumab.

Can I write you an email ?

That may not be a valid assumption. Often with proteins at low concentrations they add some carrier protein, like BSA or glycogen or something to help preserve the antibody. If you purchased the mAB there should be an information or material sheet with it.

Yes you can, it only need max 3 uL and read at 280 nm.

Romsyah Maryam Thank you.

Michael J. Benedik mAb will be conjugate with a ligand. You're right I'll buy the mAb stabilized with buffer and salts (no protein).

I plan to desalt and concentrate the mAb this is why I assume it'll be pure.

According some publications, I can skip this step so I'll need to know the concentration of the [mAb-ligand] not the mAb itself.