Urine| Hair Follicle | Oral Fluid | Blood | ETG
Hair assessments are regarded as an effective method for identifying alcohol and drug consumption. Hair strands capture long-term evidence of substance use by embedding biomarkers within the hair's fibrous structure as it grows. When hair is sampled near the scalp, it can reveal alcohol and drug exposure for an approximate duration of three months. Hair collection is straightforward, presents challenges for tampering, and is convenient to transport.
Obtaining a 1.5-inch segment comprising around 200 hair strands (roughly akin to a #2 pencil's thickness) adjacent to the scalp will yield 100mg of hair, which is the optimal amount for both screening and verification. For EtG, additional analyses, and/or evaluations beyond ten panels, a specimen weighing 150mg is advised. We suggest measuring the specimen with a jeweler’s scale. If scalp hair is unavailable, a similar quantity of body hair can be collected. References to head hair imply only scalp hair. Body hair encompasses all other hair types, such as facial or axillary.
Process Overview
The laboratory's handling of a drug test outcome encompasses four principal phases: Accessioning, Screening, Extraction, and Confirmation.
During Accessioning, the sample is initially processed into the laboratory's database. This entails ensuring the sample was appropriately sealed and transported, assigning a unique LAN (Laboratory Accessioning Number), and finalizing any other data entry not included by an electronic chain of custody system.
Screening is a preliminary rapid examination for drug presence. Though cost-efficient for dismissing drug presence in most samples, a positive screen necessitates affirmation to be legally acceptable. Samples showing a positive indication in Screening must undergo further validation.
If a sample appears positive during Screening, additional hair from the original specimen undergoes preparation for Extraction. This phase involves retrieving drugs from hair at a notably lower concentration compared to other techniques such as urine or oral fluid testing, which is why hair drug screening presents a considerable challenge.
Confirming any positive Screening result is executed using GC/MS, GC/MS/MS, or LC/MS/MS. All samples indicating possible positivity are appropriately cleansed before confirmation as necessary. The entire laboratory workflow, from Accessioning to Confirmation, adheres to both CAP (College of American Pathologists) Hair endorsement and accreditation under ISO / IEC 17025 criteria.
Advantages of hair drug testing:
Limitations:
Note: Though often labeled as "hair follicle tests", the assessment targets the hair strand rather than the follicle located beneath the scalp
