Dear All, Does anybody has any comment on using heparin as an additive to co-crystallise an RNA-binding protein? I am not asking about using it to form a complex with proteins that are know to bind heparin specifically, but using it as a general RNA analogue, when we lack the knowledge of the RNA target sequence. Thanks a lot. Wai -- Yu Wai Chen, PhD........................................Lecturer King's College London, Randall Division +44-207-848-8206 New Hunt's House, Guy's Campus, London SE1 1UL, U.K.