Students in grades 6-8 test six natural substances, garlic, raw honey, turmeric, tea tree oil, oregano oil, and distilled water as a control, by placing sterile paper discs soaked in each substance onto pre-poured agar plates and measuring the zone of inhibition around each disc in millimeters after 24 to 48 hours of incubation. The natural antibiotics effectiveness lab sheet walks through question, hypothesis, procedure, data table with two trials per substance, observations, and a written conclusion about which substance performed best.

This lab fits naturally into a microbiology, health science, or natural remedies unit study and pairs well with lessons on how antibiotics work at the cellular level. Completing it asks your homeschooler to practice sterile technique, read calipers or a ruler for precise measurement, and interpret a data table before forming an evidence-based argument in the conclusion section, skills that move well beyond basic observation into genuine scientific reasoning.