Urine| Hair Follicle | Oral Fluid | Blood | ETG
Utilizing hair testing has emerged as an effective method for detecting substance use. The fibers of growing hair strands capture biomarkers, offering a historical record of alcohol and drugs. A sample taken near the scalp can reveal drug or alcohol presence over a span of roughly three months. Hair collection is straightforward, resistant to tampering, and convenient to send.
To obtain an optimal sample, collect a 1.5-inch hair segment comprising around 200 strands (about the width of a #2 pencil) from near the scalp. This should yield 100mg of hair, suitable for general screening and confirmations. For tests involving EtG, add-ons, or more than 10 panels, 150mg of hair is ideal. We advise using a jeweler’s scale for measuring the specimen. If scalp hair is unavailable, equivalent body hair may be utilized. The term head hair specifically refers to scalp hair. Body hair encompasses other types (such as facial and axillary).
Process Overview
The laboratory process for determining drug test results encompasses Accessioning, Screening, Extraction, and Confirmation.
Accessioning is the step where samples are processed into the laboratory’s framework. It involves ensuring proper shipment and sealing of the sample, allocating a random LAN (Laboratory Accessioning Number), and completing any supplementary data entry not covered by an electronic chain of custody system.
Screening performs an initial, rapid test for abused drugs. This step is cost-efficient for ruling out drug usage in most cases, but a positive in the screening stage requires further confirmation for legal admissibility. Samples with presumptive positive results in Screening necessitate secondary confirmation.
For samples deemed presumptively positive, additional hair is extracted from the initial sample for the Extraction phase. Drugs are extracted from the hair at significantly lower concentrations relative to other methods (e.g., urine or oral fluid). This distinction makes hair drug testing notably complex.
Confirmation of any positive screening result is conducted via methods such as GC/MS, GC/MS/MS, or LC/MS/MS. All presumptive positive samples undergo washing before confirmation if necessary. The laboratory process, from Accessioning to Confirmation, is scrutinized under the CAP (College of American Pathologists) Hair designation and complies with ISO / IEC 17025 accreditation.
Advantages of hair drug testing:
Limitations:
Note: Although commonly called "hair follicle tests", these tests assess the hair strand rather than the follicle beneath the scalp.
