( ( ( ANTIBODIES , ) POLYCLONAL ) - )
(ROOT (NP (NP (NNS ANTIBODIES)) (, ,) (NP (NNP POLYCLONAL)) (: -)))
ANTIBODIES, POLYCLONAL -
(ROOT (S (NP (DT An) (NN animal)) (VP (VBZ produces) (NP (JJ polyclonal) (NNS antibodies)) (PP (IN after) (NP (NP (NN exposure)) (PP (TO to) (NP (DT a) (JJ microbial) (NN antigen)))))) (. .)))