According to a lengthy exposé in The Wall Street Journal, blood testing startup Theranos is struggling to make the very technology that made founder Elizabeth Holmes America's youngest female billionaire actually work.
I've never been afraid of needles, but giving blood is no trip to Disney World. Anytime a phlebotomist tries to sink a needle into my arm to collect blood, my plump veins roll away. Doctors stick me again and again, and I leave their offices with enough bruises on my arms to pass for a junkie.
Mr Zuckerberg made the announcement in a letter to Max on his Facebook page.
He said they are donating their fortune to the Chan Zuckerberg Initiative because they want to make the world a better place for Max to grow up in.
Mr Zuckerberg said the donation currently amounts to $45bn (£30bn).
Max was born last week, but the couple only made the news of her birth public on Tuesday.
In his letter Mr Zuckerberg said the aim of the Chan Zuckerberg Initiative is “to advance human potential and promote equality for all children in the next generation”.
The U.S. Supreme Court heard arguments today in a huge privacy dispute over drunk driving arrests. The case turns on whether police can snag blood samples from unwilling suspected drunk drivers without a search warrant.