( ( Organisms ( which ( are ( negative ( in ( this reaction ) ) ) ) ) ) ( ( are ( tested ( in ( ( a panel ) ( of ( 12 ( biochemical tests ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Organisms)) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (ADJP (JJ negative) (PP (IN in) (NP (DT this) (NN reaction)))))))) (VP (VBP are) (VP (VBN tested) (PP (IN in) (NP (NP (DT a) (NN panel)) (PP (IN of) (NP (CD 12) (JJ biochemical) (NNS tests))))))) (. .)))
Organisms which are negative in this reaction are tested in a panel of 12 biochemical tests.
(ROOT (S (NP (JJ Biochemical) (NNS reactions)) (VP (VBP occur) (PP (IN inside) (NP (NNS organisms)))) (. .)))