How should blood samples be preserved at a crime scene?

How should blood samples be preserved at a crime scene?

• A. In liquid state in plastic containers
• B. In a dry state in a paper bag or envelope
• C. In glass vials
• D. In water-filled containers

Answer: (B)

Preserving blood samples at a crime scene is critical to maintaining their integrity for analysis. Storing blood in a dry state within a paper bag or envelope is the most appropriate method because it helps to prevent contamination and degradation. Paper allows for some breathability, which is essential for moisture control; excessive moisture can promote bacterial growth and affect the sample's viability for testing. Moreover, using a paper container reduces the risk of chemical interactions between the blood and the container that might occur with some plastics or glass. The choice of a dry paper medium also ensures that the sample remains stable during transport and storage until it can be processed in a laboratory environment. In contrast, storing blood in a liquid state in plastic containers can lead to contamination and the potential for the sample to degrade. Glass vials, while sometimes suitable for other types of evidence, can break or shatter, leading to complications. Finally, water-filled containers can dilute or alter the blood sample, making it unsuitable for forensic analysis. Thus, the best practice for preserving blood samples involves using a dry state in a paper bag or envelope.

Preserving blood samples at a crime scene is critical to maintaining their integrity for analysis. Storing blood in a dry state within a paper bag or envelope is the most appropriate method because it helps to prevent contamination and degradation. Paper allows for some breathability, which is essential for moisture control; excessive moisture can promote bacterial growth and affect the sample's viability for testing.

Moreover, using a paper container reduces the risk of chemical interactions between the blood and the container that might occur with some plastics or glass. The choice of a dry paper medium also ensures that the sample remains stable during transport and storage until it can be processed in a laboratory environment.

In contrast, storing blood in a liquid state in plastic containers can lead to contamination and the potential for the sample to degrade. Glass vials, while sometimes suitable for other types of evidence, can break or shatter, leading to complications. Finally, water-filled containers can dilute or alter the blood sample, making it unsuitable for forensic analysis. Thus, the best practice for preserving blood samples involves using a dry state in a paper bag or envelope.