Property, plant and equipment and related accumulated depreciation are summarized as follows:

Fixed assets are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the asset’s estimated useful life. Land is not depreciated. The buildings were assigned a useful life of 30 years. Property and equipment other than land and buildings have useful lives ranging from 3 to 10 years. Leasehold improvements are amortized over the lesser of the lease term or their estimated useful lives.

The Company recorded depreciation expense on property and equipment of $0.6 million, which includes $0.1 million of depreciation expense on the plasma assets to be transferred (see Note 3), and $0.1 million for the three months ended March 31, 2018 and 2017, respectively.