What is the appropriate readout for determining whether you tolerized against an - (Oct/03/2014 )

If you want to tolerize mice against a certain antigen and inject the antigen without an adjuvant, what is the readout for determining whether you induced tolerization?

Maybe a little late on this, but I think (not an immunologist by any stretch of the imagination) that the readout would be lack of immunological response, i.e. no increased production of antibodies against tolerizing agent.