In preparing for her first film role as a petite, hard-laboring slave in "12 Years a Slave," actress Lupita Nyong'o sized herself up against 500 pounds of cotton, which her character Patsey picked every day.

"12 Years a Slave" is based on an 1853 memoir about a free black man tricked and sold into slavery.

Nyong'o's performance is one that has generated critical acclaim for the Hollywood newcomer and predictions she will earn a best supporting actress Oscar nomination.

Nyong'o said that director Steve McQueen showed her a part of Patsey that could not be enslaved.

SOUNDBITE: Lupita Nyong'o, "12 Years a Slave" co-star, saying (English):

"In playing her, I learned that you don't have to live a day free to know what freedom is. That it is actually a human instinct, this desire to be free."

The actress was born in Mexico 30 years ago where her Kenyan father was in political exile, but they moved back to Kenya when she was 1.

She was educated in the