Contrary to popular belief, UCSF is not exempt from sales tax in most cases. The purchase of tangible goods is generally taxable except as otherwise provided by law; the purchase of a service is generally not taxable except for certain taxable services according to California State Board of Equalization (BOE) regulations.
Additionally, purchases from vendors located outside of California is still subject to use tax. Sales/use tax rate is determined by the point of delivery.
More information regarding sales/use tax can be found here: