What is a significant disadvantage of using stem cells grown in a laboratory?

The significant disadvantage of using stem cells grown in a laboratory is the potential for contamination with a virus. This is a major concern because if stem cells become infected, they can lead to serious health complications when used in therapies, potentially harming the patient or compromising the effectiveness of treatment. Laboratory conditions must be carefully controlled to avoid such risks, but despite these measures, the possibility of contamination remains a real threat in stem cell research and application.

The other options highlight benefits or ideal situations that may not realistically apply. For example, while stem cells have the potential to enhance healing, this is not inherently a disadvantage. Similarly, ethical sourcing of stem cells is a crucial consideration but not guaranteed, making it misleading to state that they are always ethically sourced. Lastly, while stem cells can differentiate into various cell types, there can be limitations or controls in practice, meaning they do not always convert without restriction. Thus, the concern over viral contamination stands out as a significant disadvantage in using laboratory-grown stem cells.