Nature of business and summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Property, Plant and Equipment, Schedule of Significant Acquisitions and Disposals [Table Text Block]

Depreciation and amortization are computed using the straight-line method over the following estimated useful lives:

Land and buildings	20 years
Laboratory equipment	4 - 8 years
Office and computer equipment	3 years
Furniture, fixtures and fittings	5-10 years