What should not be used to treat dried blood stains on evidence?

Using moistened cloths or papers to treat dried blood stains on evidence can compromise the integrity of the sample. Dried blood is a delicate biological specimen, and introducing moisture can lead to degradation or contamination. This process may alter the chemical composition of the blood or introduce external elements that could interfere with subsequent analysis, such as DNA testing. It's crucial to preserve biological evidence in its original state to ensure accurate forensic examination and reliable results.

The other options are appropriate for the handling and preservation of evidence. Standard evidence collection bags are designed to contain and protect evidence while preventing contamination. Labeling and sealing materials are essential for ensuring that evidence maintains a clear chain of custody and remains tamper-proof. Freezing containers might be used for certain types of biological evidence to preserve it without introducing moisture, making them a suitable option under specific circumstances.