Materials such as plasticized polyvinyl chloride can be used as which control?

• A. Simulated tissue
• B. Negative (noncytotoxic) control
• C. Reference material
• D. Positive (cytotoxic) control

Answer: (D)

In cytotoxicity testing, controls are used to show that the assay can detect harmful effects on cells. A material that reliably harms cells serves as a positive cytotoxic control, confirming the test will respond when cytotoxic effects are present. Materials like plasticized polyvinyl chloride are known to release toxic plasticizers that can damage cultured cells, so they provide a consistent, expected cytotoxic response. This validates the assay’s sensitivity and helps distinguish true cytotoxic effects from artifacts. Simulated tissue and reference materials don’t inherently demonstrate cytotoxicity, and a non-toxic material would serve as a negative control to show the assay’s baseline with no harm. Hence, the best choice is a positive cytotoxic control.