# ELISA Plate coating - (Nov/06/2008 )

Hi there,

I was given 100ug of an antibody for coating an ELISA plate and I want to coat 5 wells with 100ng of this antibody. How do I make the coating antibody solution?

Typically, I would make a 1ug/ml solution and load 100ul per well to give 100ng per well but I am confused because I don't know the concentration of the antibody I was given (all I know is that I have 100ug) so I can't use the C1V1=C2V2 equation.

-Newbie74-

Do you know the volume of the antibody?

-Minnie Mouse-

No, but I could just measure it. I am guessing it is about 300ul, therefore 100ug/300ul= 0.33ug/ul? right?

-Newbie74-

QUOTE (Newbie74 @ Nov 6 2008, 08:10 PM)
No, but I could just measure it. I am guessing it is about 300ul, therefore 100ug/300ul= 0.33ug/ul? right?

yes...

Would you pulse centrifuge the eppendorf tubes and then use a pipette to see whether it is 300ul ± 10ul?

-Minnie Mouse-

You have such a small volume go ahead and centrifuge and measure the volume to determine conc. If it was higher you could do OD 280 (quartz cuvette) and divide by 1.4 to get mg/ml.

-sgt4boston-

I agree with sgt4boston if you have larger volume of anitbody.

-Minnie Mouse-