Theranos founder Elizabeth Holmes should spend 15 years in prison

and pay $800 million in restitution to investors defrauded in the blood

testing start-up, U.S. prosecutors recommended late on Friday.

The Department of Justice recommendation, made in a court filing,

came as Holmes prepares to be sentenced next week.

"Considering the extensiveness of Holmes' fraud...

the sentencing of 180 months' imprisonment would reflect the seriousness of the offenses

provide for just punishment for the offenses, and deter Holmes and others," the prosecutors said.

California not to send her to prison.

Any sentence would likely be served concurrently.

Prosecutors said she lied to investors from 2010 to 2015 by promising Theranos