( Antibodies ( ( are ( specific ( for ( only ( one antigen ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Antibodies)) (VP (VBP are) (ADJP (JJ specific) (PP (IN for) (NP (RB only) (CD one) (NN antigen))))) (. .)))
Antibodies are specific for only one antigen.
(ROOT (S (NP (DT An) (NN antibody)) (VP (MD can) (VP (VB match) (NP (NP (CD one) (NNS types)) (PP (IN of) (NP (NNS antigens)))))) (. .)))