Then he told me he'd tried the same test on guinea pigs.

He knew they were still using people as their guinea pigs.

And so he became a guinea pig, a test run.

So now she felt like a guinea pig, on top of everything else.

"Good thing for you she had a guinea pig to test it out on first."

It is sometimes used to find other guinea pigs if they are running.

Once, he was paid to be a medical guinea pig.

"Make you a guinea pig, just like her, before they risk any of their own with this."

At the age of 48 he bought his first guinea pig.

"I'm not going to practice this on my patients like guinea pigs to see if it works."