Assertion: d cysteine | /r/ObjectUse | used as negative control
Facets:
value: for l-cysteine
type: TRANSITIVE-OBJECT
value: originally
type: MANNER
Source sentences:
text: When we examined the production of H 2 S from brain homogenates, we found that H 2 S was produced from d-cysteine, originally used as a negative control for l-cysteine (27).