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Recommended Methods of Evidence Sample Selection and Collection
for Wildlife DNA Forensic Analysis.

DNA is a relatively stable molecule but will degrade in tissue over
time unless preserved. Samples can be preserved in two ways:

By placing the sample in preservative buffer supplied by our
laboratory or by drying the sample in to us.

DNA Sampling Kit

Sample Selection

Sampling Instructions & Kit Availability

 


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DNA Sampling Kit
A basic DNA Sampling Kit is recommended for preparing samples for DNA analysis
and should include:

  • Sampling equipment (scalpels, tubes, buffer),
  • Disposable gloves
  • Paper towel,
  • Zip sealed bags,
  • Swabs,
  • A Permanent marker

Sampling kits for each of the sample collection types are available from the Wildlife Forensic DNA Laboratory at cost (Kit components, associated costs and order form).


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SAMPLE SELECTION Selecting a Sample from a Kill Site

Gut Pile Tissues:
Samples associated with a kill site are most commonly the remains of the animal.
The best samples from a kill site are brain, heart, and red muscle. DNA in these samples will degrade in 3-4 weeks in warmer temperatures until preserved. Heart and muscle samples should be reddish in colour and this may require burrowing deeper into the tissue. Kidney, spleen, liver, and stomach can be sampled if the sample is not older than 1 week. These organs undergo rapid enzymatic decay after 1 week of environmental exposure to warmer temperatures. Hide samples with attached reddish tissue can also provide sufficient DNA for testing.

Blood Stains:
DNA in a blood sample can undergo rapid degradation in less than one week.
Blood frozen in snow and ice should be collected.
Blood stains at a kill site on leaves, dirt or rocks may be problematic due to contamination by microorganisms. Samples may be placed in a container with desiccant material to absorb any moisture.

NOTE: Animal remains and blood which are frozen at the kill site during the winter months will have extended periods of preservation.


Selecting a Sample Associated with a Suspect
Samples commonly associated with a suspect are frozen meat samples and blood.
Meat samples are often confiscated from the suspect's freezer. Animal remains may also be present. See above for the most appropriate samples for analysis.

Blood stains are found on two sources:

  • Non-absorbent material, eg. metal and nylon
  • Absorbent material, eg., cloth

Blood stains on absorbent material may be problematic as dyes and chemicals in the material can contaminate a sample and inhibit analysis.

Although some samples may be problematic for analysis, i.e. samples with low yields or poor quality DNA, all samples associated with the investigation should be submitted because the degree of DNA degradation is dependent on several variables and the amount and quality of DNA cannot be assessed until a DNA extraction has been performed in the laboratory.


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Sampling Instructions and Kit Availability

Sample Handling
To avoid contamination of a sample by the collecting officer or by other animal samples associated with an investigation, the sample collector should wear clean gloves to handle and prepare each sample. Disposable sampling equipment are provided for sample preparation.

Preparation of Meat, Organ and Hide Samples
Samples can be processed and shipped using preservative buffer:

  • Label the sample tube using a permanent marker.
  • Using clean latex gloves to handle the sample, with a clean scalpel shave off a small portion from the outside of the tissue and discard.
  • Using a new clean scaplel, cut a piece of tissue approximately the size of a 1 inch spaghetti noodle (7.5 mg) from the inside of the tissue
  • Add the sample to the buffer
  • Repeat this process and place the second sample in the tube containing buffer (provided).
  • Tubes can be shipped at room temperature. Excess tissue sample should be kept frozen at the respective facility.

Preparation of Wet Blood Stains
Samples from a kill site are commonly found on leaves or rocks. If the stain is large enough, sample the blood using a dry swab without contaminating it with leaf material or dirt. Air dry the swab for a few minutes, then place into the sealed tube provided and ship at room temperature.

If the blood stain is small, save the leaves, etc., and place the blood stain attached to the organic material into the desiccant tubes. The sample will be stored and shipped dry.

Preparation of Dried blood stains
Samples located on material such as clothing, knives, guns, etc. should be shipped at room temperature in a well sealed package. Blood stains may have to be cut or isolated from material.

If blood stains are located on an object that cannot be shipped, collect the stain using a clean swab moistened with Phosphate Buffered Saline (PBS), dry the swab and ship to the laboratory in a well-sealed tube or container.

Preparation of Hair and Feather samples
Samples should be kept dry and shipped at room temperature in envelopes or a sealed plastic bag. DNA is isolated from the root of the hair shaft and therefore it is extremely important that all hairs be plucked not cut.

Preparation of Processed meat samples
Samples for quantification such as sausages, or cooked meat should be shipped in a cooler with ice. The entire meat sample should be submitted to allow an accurate assessment of the species of origin or the percentage of game animal tissue within sample. Freeze the sample and ship in an ice-packed sealed cooler.

Preparation of Whole blood samples
Blood from live-trapped animals can be collected on blotting paper. Using the needles provided, draw blood from the specimen. Blot blood from the animal onto leaflet inside the insert. Air dry for five minutes and replace insert into envelope. DO NOT SEAL ENVELOPE. Then place envelope into a sealed plastic bag with a desiccant pouch. The blot should be shipped at room temperature.

The blot should be shipped at room temperature. If using a vacutainer, the remaining blood should be frozen and kept at the respective facility.

Preparation of Fin Clips
Fin Clips can be removed and placed into vials containing a preservative buffer. At least two fin clips
are recommended. Samples can be sent dry.

Preparation of Bone samples
Bone samples from teeth, antlers and carcasses can be used for DNA analysis. Most often bone samples are provided from historic samples. A tooth will be removed from the skull to extract the DNA within the root. The tooth will be cut at the base just above the root allowing the rest of the tooth to be reinserted into the skull for any subsequent morphological measurements.

Samples can also be obtained by drilling into a non-obtrusive portion of the bone fragment with a minute drill bit and removing the bone powder for DNA extraction. The largest bones will be targeted to prevent damaging smaller bone specimens. We have successfully applied this extraction protocol on a number of historic moose and elk antlers and bowhead and North Atlantic right whale bones from the 1500s
with minimal impact of the actual specimen. Past studies have also employed similar techniques for extraction of DNA from bones. Yang et al. (1997) utilized a 3mm drill bit to obtain 0.15-0.5g of bone
dust from ancient skeletal specimens for successful DNA extraction.


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Evidence Disposal Policy
All evidence will be disposed of 60 days following the completion of a report for DNA analysis unless otherwise notified. Any requests for the return of material such as clothing, knives, guns, etc as well as processed meat samples must notify the Wildlife Forensic DNA laboratory Forensic Scientist by email prior to the 60 days and supply a shipping account number.

Shipping Samples/Continuity of Evidence
Samples can be shipped via courier or registered mail. The packaging/coolers should be sealed and signed by the investigator. If the samples are frozen, they should be shipped in a cooler with ice packs with the label "PLEASE KEEP FROZEN" clearly marked on the outside of the cooler. Other shipments require double packaging to protect against shipping damage. The seals will be examined following transportation to ensure the package was intact during shipment. Samples submitted to the laboratory for analysis are signed in as evidence and placed in a secure evidence room. A case submission form must be sent with the samples. These forms can be found HERE

Samples can be shipped to:

Sarah Dolynskyj , Forensic Scientist
Wildlife Forensic DNA Laboratory.
Natural Resources DNA Profiling & Forensic Centre,
DNA Building, Rm A109 
2140 East Bank Drive, Peterborough, Ontario, Canada, K9L 1Z8
Phone (705) 748-1011 ext. 1687.
Fax (705) 748-1132
E-mail: forensiclab@nrdpfc.ca

 

Trent University Wildlife Forensic DNA Laboratory
DNA Building, Rm A109
2140 East Bank Drive, Peterborough, Ontario, Canada, K9L 1Z8
Phone: (705) 748-1011 x7687| Fax (705) 748-1132
Email: forensiclab@nrdpfc.ca