If a participant withdraws from a study, what can they request regarding unused portions of their stored samples?

When a participant withdraws from a study, they have the right to request the destruction of their unused portions of stored samples. This aligns with ethical standards and principles of informed consent, which prioritize the autonomy and preferences of participants regarding their biological materials. Respecting a participant's wishes to destroy their samples is important to ensure their privacy and control over their personal information, as well as to uphold ethical conduct in research.

In many institutions, specific guidelines and regulations allow participants to make such requests to protect their interests and maintain trust in the research process. It’s crucial for stakeholders involved in medical research to communicate clearly to participants about their rights concerning their samples throughout the study.

Regarding the other options, the choice to store samples indefinitely is generally not permitted as it could violate ethical standards and regulations regarding the management of human tissues. Requesting additional testing is often not an option since it implies ongoing participation in the research, which is contradictory to their withdrawal. Lastly, saying that participants cannot make any requests would go against established ethical guidelines that empower participants to have control over their biological materials.