Hi Eduard,

You can theoretically calculate the number of maleimide groups available for Ab binding and try out few ratios that would work. From my understanding, Abs are quite bulky and you do not need too many of them on one single particle, which would affect the particle intake. Also, many Abs on the NPs could compete for the same receptor to bind (Not sure how that would affect the particle intake!). Having said that, you could try 10 maleimide : 3 Abs, 20:3, 30:3 and then work out which one is more effective for cell studies (If none of them work, obviously you need to increase the number of Abs).

You really cannot say how many Abs are attaching to one single NP unless you have fluorescence tagged Abs. If you need to know the exact number of Abs, then I would suggest you to go for flourescent tagged Abs.

Hi Edward and Ramya

I think Edward asking about ratio not the number, Practically it is difficult to conjugate nanoparticles with antibodies in number. Edward if you will take 1:10 ratio with respect to nanopartcles to antibody or optimize this ratio with respect to your work. You will definetly get the good results. Find the paper related to your work.

 http://www.ncbi.nlm.nih.gov/pubmed/24601828 

Thank you for the help gentlemen! Best of luck in your research!

EF

Dear Eduard,

We recently published a manuscript whereby we used a protein-lipid nanoparticle to target different human blood immune cells.

We estimate that each nanoparticle (60 nm hydrodynamic radius) had ~16 targeting antibodies, and this provided very good targeting.

I hope this is able to help.

Josh

http://pubs.rsc.org/is/content/articlelanding/2016/nr/c6nr00506c#!divAbstract