The details are as follows:

The evidence preservation containers in a forensic evidence collection kit need to possess various characteristics to ensure the integrity, stability, and traceability of the evidence, providing reliable support for subsequent forensic analysis and case-solving. The details are as follows:

Physical Characteristics

• Sealability: The preservation containers must have excellent sealing performance, such as lids with sealing gaskets or sealed zippers, to prevent the entry of external air, moisture, dust, and other pollutants. This avoids the contamination, oxidation, or degradation of the evidence, which is particularly crucial for biological samples like blood and tissues.
• Robustness: They should be made of durable materials, such as high-quality plastics, glass, or metals, and be able to withstand a certain degree of external impact, extrusion, and friction. This protects the evidence from damage during transportation and storage, ensuring the integrity of fragile or deformable evidence, such as glass fragments and bones.
• Diversity in Size and Shape: To accommodate different types and sizes of evidence, the preservation containers need to come in a variety of sizes and shapes. For example, small plastic bottles are used to store hairs and fibers, and large plastic bags or boxes are used to preserve larger items like clothes and weapons.

Chemical Characteristics

• Chemical Stability: The container materials should not react chemically with the evidence being preserved, avoiding any impact on the chemical composition and properties of the evidence, and ensuring that the original characteristics of the evidence are retained. For instance, the chemical components in a plastic container should not leach out and interfere with the DNA analysis of a biological sample.
• Non-corrosiveness: The containers themselves should not be corrosive to prevent corrosion and damage to the evidence. For metallic evidence, if the preservation container is corrosive, it may cause the surface of the evidence to rust or corrode, affecting the trace and physical evidence information on it.

Biological Characteristics

• Biocompatibility: For biological samples, the preservation containers should have good biocompatibility, neither inhibiting nor promoting the growth of microorganisms, and having no adverse effects on biological components such as cells and DNA. For example, the container for storing blood samples should not contain substances that can damage blood cells or degrade DNA.
• Sterility: When collecting and preserving biological evidence that may be used for microbial detection or cell culture, etc., the containers must be sterile to prevent contamination of the evidence by external microorganisms and to avoid affecting the accuracy of the test results. Usually, methods such as high-temperature sterilization and chemical disinfection are used for aseptic treatment.

Other Characteristics

• Clear Identification: The surface of the container should have enough space for clearly marking relevant information about the evidence, such as the collection time, location, case number, type of evidence, etc., and the marked content should be able to be maintained for a long time without fading or blurring. This facilitates the quick and accurate identification and traceability of the evidence during subsequent investigations and analyses.
• Traceability: Some advanced evidence preservation containers may be equipped with traceable identifiers such as electronic tags or QR codes. By scanning these identifiers, detailed information and circulation records of the evidence can be quickly obtained, enabling the whole-process tracking and monitoring of the evidence from collection to analysis.