A North Carolina public school teacher was fired after having students share needles to determine their blood types for a class experiment.

During the Oct. 24 experiment, Overhills High School biology teacher Miyoshi McMillan had 11 students use lancets to prick their fingers, and then had a class of 5 students later that day use the same lancets, county spokesperson Patricia Harmon-Lewis told The Huffington Post on Wednesday.

Students who chose not to do the blood test experiment were given an alternate assignment to write a five-page paper, according to local newspaper The Fayetteville Observer. One concerned student instead left class to call her parents, who immediately alerted the assistant principals.

"They were like, 'Stop the lab! Stop the lab!'" McMillan told area news outlet WRAL.

Although the lancets were swabbed with alcohol before being reused, alcohol is not always sufficient to kill blood-borne pathogens like hepatitis or HIV.

"The administration called every parent of every child as soon as we realized it happened," Harmon-Lewis said. "Afterwards they sent home a notice telling them to go to their primary care physician or urgent care in order to have baseline bloodwork drawn."

McMillan, who was still being paid as a substitute teacher while she worked to get her full teaching certification, was fired the same day. She says the school is overreacting.

"I believe it's really been blown up and it's been a character strike against me," said McMillan, per ABC local affiliate WTVD-TV.