Evidence Handling Guidelines
Please follow these guidelines to prevent potential degradation and contamination of DNA evidence.
If you have any questions, please contact us at 909-793-3820 or info@puregoldforensics.com.
Degradation of biological evidence is most commonly caused by exposure to moisture and heat, which encourages the growth of bacteria. This can lead to the destruction of the DNA and the possibility of incomplete or no DNA typing results being obtained. Contamination of samples, either by coming into contact with each other or with DNA from a person handling the sample, can lead to un‐interpretable DNA results.
Considerations for Handling
In order to avoid contamination of DNA evidence, Pure Gold Forensics recommends the following:
- Always wear latex gloves when handling biological evidence.
- Change gloves between the handling of each item of evidence.
- Process biological evidence on a clean area (such as a fresh piece of butcher paper). Use a 10 % bleach solution to clean areas at which biological evidence will be handled.
- Be careful not to talk excessively over biological evidence. Wear a mask if necessary.
- Only work with one piece of evidence at a time.
- Never allow items of biological evidence to come into contact with each other.
In order to avoid the degradation of DNA evidence, Pure Gold Forensics recommends the following:
- Do not expose biological evidence to excessive heat or humidity.
- Allow biological evidence to air-dry prior to packaging.
Considerations for Packaging
Where possible, biological evidence should be packaged as described below:
- Dried Stains. After stains have been air dried, store frozen or refrigerated in separate paper containers (e.g. bags, envelopes, cardboard boxes). NEVER USE PLASTIC CONTAINERS.
- Liquid Blood Samples. Store refrigerated in original glass/plastic tubes. NEVER FREEZE LIQUID BLOOD SAMPLES as glass tubes can shatter.
- Other. Biological evidence such as tissue samples, organ samples, bones, and liquid urine samples can be stored in air‐tight, sterile plastic containers.
Considerations for Shipping/Submission
A. All evidence shipped to Pure Gold Forensics with the evidence submission form. This form is available on our website.
B. All evidence should be hand‐delivered or shipped via priority overnight mail service for delivery on a non‐holiday, business day only.
C. Dried Stains should be shipped in a sealed box or sturdy, sealed envelope at room temperature.
D. Liquid Blood Samples should be packaged in a styrofoam tube package or wrapped in bubble wrap secured with tape. The individually packaged tubes should then be placed in a cardboard box containing packing material that will provide protection from breakage. The samples should be shipped at room temperature.
E. Liquid Blood Samples known to be HIV or Hepatitis positive require special care when being shipped. These types of samples should be packaged in an ‘infectious substance shipper’ (available at jitcertified.com, saftpak.com, dgsupplies.com, etc). A proper shipping tag for dangerous goods must be affixed to the outside of the package. The samples should be shipped at room temperature.
F. Other (samples such as organ samples and bones stored in sealed sterile plastic containers). The individual sealed plastic containers should be placed on dry ice in a styrofoam container.
G. Ship all evidence to:
Pure Gold Forensics
Attn: Evidence Submission
303 Brookside Avenue, Suite 140
Redlands, CA 92373