This poster presents strong scientific evidence that monoclonal antibodies raised against beta glucans from MRL´s Pleurotus ostreatus also recognize beta glucans from other MRL products which is very interesting regarding their tertiary structure. The importance of the tertiary structure of beta-glucans is due to the fact that all beta-glucans with anti-tumor activity exhibited this tertiary structure. (Presented at the 12th International Chemical and Biological Engineering Conference (CHEMPOR 2014), organized by the Department of Chemical Engineering of the Faculty of Engineering - University of Porto and Ordem dos Engenheiros (the Portuguese Engineers Association), held in Porto, Portugal, between the 10th and 12th of September, 2014