What is the correct protocol regarding supplier changes during an ongoing study?

The correct protocol regarding supplier changes during an ongoing study emphasizes the importance of maintaining study integrity and consistency. This protocol dictates that suppliers should not be changed until the study is complete to ensure that the experimental conditions remain stable and that the data collected are reliable and valid.

Changing suppliers in the midst of a study could introduce variability that may compromise the outcomes and the reproducibility of the results. Different suppliers may provide animals or materials that vary in genetic background, health status, or environmental conditions, all of which could significantly affect the study's findings.

Maintaining the same supplier throughout the duration of the study helps to control for these variables, ensuring that any observed effects can be confidently attributed to the experimental interventions rather than differences in supplier quality or product characteristics. Ensuring consistency in sourcing is a critical aspect of rigorous scientific research, which supports the reliability and validity of conclusions drawn from the study.

Other options suggest practices that could undermine the fidelity of the research, such as changing suppliers for pricing benefits or variety, which are not aligned with maintaining the integrity of the study. Additionally, while regulatory approval may be necessary for changes that significantly impact study design, it is not a blanket requirement for supplier changes under all circumstances, especially if they might affect the study’s