Advanced Instrumentation Support at Research Universities

I’ve been thinking lately about the various mechanisms that research institutions use to both acquire and then subsidize advanced instrumentation such as MRI’s, Mass Specs, or Two Photon Microscopes. Obviously there are the direct charges to research grants, but in practice, that may not be enough–especially when there are technician salaries, depreciation costs and service contracts to worry about. So here’s a bleg: how does your institution support such shared equipment?  Are there cross-subsidies such as start-up packages?