Collecting Samples for Forensic Testing

Special Instructions: In Forensic Cases, each specimen container needs to be individually labeled and sealed. A tamper-resistant seal should be placed on the container so as to prevent the potential for tampering. Appropriate history and chain of custody documentation should be included. Specimens should be packed securely to prevent breakage. The package should be forwarded by a certified (return receipt) service. For forensic specimens, it is especially important that the recommended specimen labeling instructions and recommended shipping instructions are followed.

Forensic Collection Kits: NMS Labs provides a variety of specimen Forensic Collection Kits that ensure specimen integrity. NMS Labs will accept specimens in any shipping package (collection kit, etc.); however, failure to meet forensic collection, identification and transport requirements may jeopardize the acceptance of analysis results as evidence for use in criminal, civil, judicial or administrative proceedings. Please include the chain of custody form(s) in the same shipment as the specimens. Enclose the form(s) in a separate plastic bag to prevent contamination.

NMS Labs’ INTEGRIKIT® and PROTECTIKIT® collection and shipping kits are designed for the collection and transport of blood, urine and hair specimens, in a manner which ensures chain of custody and preservation of specimen integrity. The INTEGRIKIT® and PROTECTIKIT® serve as guides to assure the proper collection of the required volume of blood, urine and hair for the process of screening and confirmation testing. The kits contain information on appropriate container types for specimen collection, a case history form, chain of custody documents and specimen integrity seals. A cold pack is provided in the kit where appropriate. A detailed protocol for use is enclosed within each kit. To order collection kits and supplies please call NMS Client Support at (866) 522-2206.

Collection Kits

Postmortem Analysis

Guidelines for Special Cases

Deaths During Hospitalization: In hospital death cases, it is very important to collect and preserve blood and other samples taken on admission, as well as specimens drawn during the hospital stay. These specimens, which may contain the highest concentrations of the causative agent(s), are often discarded soon after the patient is discharged or dies. Immediate collection and preservation of these specimens, with chain of custody, may be crucial in resolving the case. In addition, all medications administered in the hospital should be listed. Physical evidence including IV bags and lines, in-room biological waste containers, etc. should also be collected.

Please contact Client Support to arrange consultation should a hospital-related death appear to be suspicious in nature.

Unusual Cases or General Unknown Cases: Please call NMS Labs for an initial consultation with one of our forensic toxicologists prior to performing the autopsy, or before the body is unavailable for procurement of additional specimens. Our forensic toxicologists will assist you in determining the appropriate types and amounts of specimens. We will recommend container types, preservatives, storage and shipping procedures. We can also help determine what other physical evidence from the death scene should be collected for analysis.

Materials Found at the Crime or Death Scene: Fully describe materials found at the crime or death scene and any materials believed to be involved (what, where, how much, etc.). If these substances are of unknown identity and a forensic analysis is needed, package them separately and send them to the laboratory with all available information. These materials may include (but are not limited to) pharmaceuticals, street dosage forms, drugs, syringes, liquids, botanicals and other suspicious, unidentified substances. These materials are sometimes overlooked, but later may be useful in resolving case issues. The Criminalistics Division of NMS Labs will analyze all materials found at the crime scene.

Embalmed, Fixed or Decomposed Tissue: The analysis of (formalin) fixed, embalmed and/or severely decomposed specimens presents unique and difficult challenges to the laboratory. In some cases, special preparation and handling, above and beyond that required for "normal" postmortem specimen is requested. In such cases, additional surcharges may be imposed for these services. To determine if additional, special preparation and handling is required, contact NMS prior to sending these types of specimens.

Formalin Fixed: In addition to the tissue(s), send at least 20 mL of the fixing solution. Toxicants in the tissues may leach into the solution.

Embalmed Body: If the body has been embalmed (even partly) prior to the autopsy, send samples of all embalming materials (along with their names and compositions) separated from the autopsy specimens (preferably in a separate package).

Post-mortem Specimen Collection

For post-mortem specimens, it is especially important that the recommended labeling and shipping requirements are followed. Post-mortem specimens and cases are considered to be forensic in nature. Preservation of the chain of custody is of critical importance for all postmortem specimens.

Blood: Each blood specimen should be identified as to anatomic site of origin (e.g. femoral vein, left ventricle, etc.). NMS prefers to receive both heart and peripheral blood (e.g., femoral blood). If you suspect poisoning by fluoride, oxalate or potassium, collect at least 10mL of blood without preservative and indicate the poisoning issue on the analysis requisition.

Femoral Blood: Collect at least 10mL femoral blood if available at the time of autopsy. Collect specimen, using a clean knife, by cutting off the iliac veins making sure to avoid the arteries. Before cutting, press the blood in the upper portion of the iliac veins. Cut and press the blood in the popliteal and femoral veins into the tube. The blood from both sides is pooled. Avoid the blood in the lower vena cava. Add potassium fluoride to a concentration of 1% or place blood specimen directly into a gray top Vacutainer® tube (or equivalent) containing a fluoride/oxalate preservative. This preservative will prevent alcohol formation and can slow the breakdown of drugs due to bacterial or enzymatic actions.

Blood samples drawn from peripherally located sources away from parenchymal tissues and organs will provide samples that are less likely to be subject to postmortem drug/chemical redistribution. Such redistribution may cause falsely elevated blood concentrations. This occurs to a very significant extent in heart, lung and other blood pools near major organ systems. Such blood pools are acceptable for screening purposes, but for most substances, quantitative confirmation should be performed in peripheral blood.

Urine: Collect up to 40mL urine. Record the appearance, color, odor and total volume of urine in the bladder. Because most urine is translucent, wrap the container in foil to exclude light or use opaque plastic containers. This will protect against photo-decomposition of light sensitive substances such as phenothiazines and LSD. If the bladder is found empty, collect up to 5 g of the trimmed bladder.

Other Liquid Biological Specimens

Antemortem Hematomas: Place each specimen in a separate container stating the location of hematoma and estimated age of the lesion. These instructions are especially important when death is delayed following trauma and it is necessary to determine the concentrations of toxic substances at and around the time of trauma infliction.

Bile or Gall Bladder: Send up to 10mL of bile or gall bladder contents in one container. If there is less than 3mL bile, also send a portion of the gall bladder (approximately 3g). Send bile in a tube without preservative (red top Vacutainer tube or equivalent) or in a screw-capped plastic vial.

Vitreous (Eye) Fluid: Collect vitreous from one eye and then wait 3 hours to collect vitreous from the other eye. Send vitreous fluid from each eye separately in screw-capped, foil-wrapped plastic vials. Vitreous fluid is translucent and needs light protection to prevent potential photo-decomposition of substances such as LSD and phenothiazines.

Gastric (Stomach) Contents: The total amount, appearance (including recognizable constituents), color, and odor found during the initial examination should be noted. Intact tablets, capsules or other objects or materials should be packaged separately and identified as being found in stomach contents. Mix the remainder of the stomach contents and send up to 40mL of a representative sample. If the stomach is "empty," trimmed portions of the stomach wall totaling up to 10 g may be analyzed.

Solid Biological Specimens

Duodenal Contents: Note the appearance, color, odor, presence of tablets or other objects found in duodenal content separately. Collect up to 40mL or grams of a representative sample noting the total amount, appearance, and odor as in "Gastric (Stomach) Contents" above.

Contents of Other Portions of the Intestinal Tract: Those samples should be handled individually and similarly to the gastric or duodenal contents specimens noted above. Tying off and sending sections "sausage style" may also be acceptable.

Nails: In postmortem cases, the entire (excised or pulled) nail should be submitted. Each nail should be harvested and packaged separately in individual plastic bottles or bags. Label each bottle with the mass of the nail collected and its source, e.g., right index finger.

Liver, Kidney, Brain or Other Tissue Specimens: Send representative samplings of other tissue specimens (liver from suspected therapeutic medication overdoses, lund from suspected inhalation poisoning, etc.) Send approximately 10 g of each tissue specimen in separate containers, labeled with tissue type and anatomical site.

Injection Sites: Excise the surrounding skin and subcutaneous tissue. Place each excised site in a separate container, identify the site from which the samples were taken, and note their age and appearance. Send syringes found at the death scene along with injectable drug vials, spoons, and other IV drug paraphernalia in separate individual containers to avoid cross-contamination.

Hair: Hair is useful for drug use history and other toxicant or exposure determinations. Hair is also useful in cases of suspected chronic poisoning or remote acute poisoning that results in death.

There are two primary methods to collect hair samples – PROTECTIKIT® hair collection kit recommended.

Recommended method: Use an NMS Labs PROTECTIKIT® hair collection kit designed specifically to facilitate collection of hair specimens. Directions for use are included in the kit. To order kits, call us. Cost is $11.00 ea.

Alternate Method: If an NMS PROTECTIKIT® hair collection kit is not available, head hair may be collected as follows:

1. Along a line drawn across the middle of the back of the head from the center of one ear to the center of the other, gather a lock of hair at least the thickness of a pencil, and tie it together near the root end (near the scalp) using a small string or a rubber band.
2. Cut the hair as close to the scalp as possible without cutting the scalp.
3. Maintain the horizontal position of the hairs in the bundle by wrapping the cut section in aluminum foil or plastic wrap.
4. Indicate the root-end and tip-end by marking the foil or plastic wrap with a permanent market or with a paper label. Do not use tape directly on the hair.
5. Place the specimen in a clean, dry, labeled paper envelope for shipment to the laboratory. Note whether bleaches, hair dye or medications (e.g. selenium or minoxidil) were used.