A selection of the most dramatic moments from the vice-presidential debate in St Louis.
Biden's emotional moment
Biden has emotional moment
Mr Biden becomes emotional when he talks about what it was like to be a single parent, after his wife and daughter were killed in a road accident.
He talks about the challenges of not knowing whether his two sons would survive.
He gets by without having to dab away a tear, however, as he did at one appearance in front of Delaware delegates at the Democratic Convention.
'It ain't so Joe'
Palin turns on 'folksy' charm
Mrs Palin turns on her "folksy" charm in reaction to Mr Biden's comment that her running mate, John McCain, would continue the policies of President Bush's administration.
Mrs Palin promised an extra credit to third-grade students, in a class taught by her brother in Alaska, if they stayed up to watch the debate.
'McCain is no maverick'
Biden: McCain is no maverick
Mr Biden reacts passionately to Mrs Palin's claims that the Republican presidential candidate, John McCain, is a maverick who "gets the job done".
Mr Biden says the senator is "out of touch" on the economic crisis - and is "no maverick" on the crucial issues being discussed by ordinary Americans around the kitchen table.
What does a VP do?
Biden and Palin on VP role
Mrs Palin discusses a statement she made in July, when she implied that she did not know what vice-presidents do.
She says it was a lame joke that nobody got, adding that she certainly understands what the role entails. Mr Biden questions whether she means that one of his jokes fell flat as well.
VP candidates debate bailout
Mr Biden says the economic policies of the last eight years have been the worst the United States has ever seen.
He says letting Wall Street "run wild" has contributed to the problem.
Mrs Palin says a good barometer of whether the economy has been through good or bad times in the economy, is to ask soccer parents how they have been affected.
Palin attacks 'white flag'
Palin berates Biden's 'white flag'
Sarah Palin accuses Barack Obama and Joe Biden of waving a "white flag of surrender" as she clashes with her Democratic opponent over Iraq.
But Mr Biden says Mr Obama has offered a clear plan for dealing with Iraq, and that Mr McCain is "odd man out" on the issue.
Palin on climate change
Palin on climate change
Mrs Palin acknowledges that human activities may contribute to global warming, but also says natural cycles are part of the picture.
She says she doesn't want to argue about the causes of climate change, but that she wants to argue about "how are we going to get there to positively affect the impacts?"
The BBC's Kevin Connolly says her answer suggested that "she couldn't quite remember the details of a hastily learned answer".