Officials said Miyoshi McMillan of Overhills High School in Spring Lake conducted a lab Oct. 24 on blood typing.
School spokeswoman Patrician Harmon-Lewis says McMillian used a lab kit that included synthetic blood and seven lancets used to obtain drops of blood for testing.
Harmon-Lewis says McMillan provided the lancets for each lab group. She said after the students used the needles, they used alcohol swabs and saved the needles for the next class to use.
The school sent letters home with every student in the biology classes.
McMillan began as a substitute teacher in 2009.