In this paper we present a description of negation cues and their scope in biomedical texts, based on the cues that occur in the BioScope corpus. We provide information relative to the ambiguity of the negation cue and to the type of scope, as well as examples. We show that the scope depends mostly on the part-of-speech of the cue and on the syntactic features of the clause. Although several studies have focused on processing negation in biomedical texts, we are not aware of publicly available resources that describe the scope of negation cues in detail. This paper aims at providing information for producing guidelines to annotate corpora with a negation layer, and for building resources that find the scope of negation cues automatically.