What is the appropriate primary container for collecting and preserving dried blood from a surface?

The appropriate primary container for collecting and preserving dried blood from a surface is folded paper. This choice is based on the properties of the materials and the preservation needs of biological evidence.

When dealing with dried blood, it's crucial to avoid contamination and preserve the integrity of the sample. Folded paper is often used because it allows the sample to be transported without being compressed or disturbed, which could compromise the evidence. Additionally, paper is breathable, reducing the risk of moisture buildup that could lead to microbial growth or degradation of the blood sample. This method also minimizes the risk of the evidence coming into contact with any residues that might be found in plastic, glass, or sealed containers.

Other options do not suit the specific needs of transporting dried blood. For instance, a plastic bag may create a humid environment that is detrimental to blood samples. Glass vials, while sturdy, can also improperly contain the sample and may not provide the optimal environment for preservation. Sealed jars, while good for preventing contamination, can trap moisture, which poses the same risk of degradation as plastic bags, making them unsuitable for this type of evidence collection.