You could check if the size (nm) of you liposomes changes. Adding protein to the liposome also changed the zeta-potential (mV). Or you could check if your conjugated liposomes bind to the antigen and control liposomes don't.

Messerschmidt, S. K., A. Kolbe, D. Muller, M. Knoll, J. Pleiss and R. E. Kontermann (2008). "Novel single-chain Fv' formats for the generation of immunoliposomes by site-directed coupling." Bioconjug Chem 19(1): 362-369.

As suggested previously, you would first have to separate the unbound antibodies from the liposomes by dialysis. I would then set up a simple lateral-flow assay in which the strip has the antigen deposited as a test line. The liposomes, containing a suitable visible dye, would then be allowed to flow along the strip. If the liposomes bind to the antigen line, the attachment of the antibodies to the liposomes would be confirmed. A more positive way to ensure antibody-liposome attachment would be to include a coupling agent into the liposome bilayer. A large number of procedures for doing this can be found in the literature.

Thankyou so very much Richard A Durst i think i should go with a coupling agent to ensure antibody-liposome attachment .

Kirstin A Zettlitz Avinash Singh Patel

ill follow your guide lines definitely as as i need to know the changes after and before the combination liposomes and antibodies

thanks alot

If your Ab has a conjugated enzyme like as HRP, you can easily check the conjugation/binding/... of the Ab to liposomes by adding respective substrate to the dialysised solution of liposome+Ab. The visual observation of attached liposomes on NC membrane may not reach easily in all situations.