The Chain of Custody (CoC) in phlebotomy ensures the integrity and traceability of a collected specimen. It is a chronological documentation trail that records the sequence of possession, handling, and transfer of a medical sample from collection until its final disposition. This process confirms the specimen analyzed is the one taken from the specific patient and that it has not been altered or tampered with. Maintaining this secure path is paramount for generating accurate and reliable test results, which directly impact patient diagnosis and treatment decisions.
Defining the Legal Requirement for Sample Integrity
The fundamental purpose of the Chain of Custody is to establish sample integrity and non-repudiation, providing a defensible record of the specimen’s history. This procedure is especially significant when test results may be used in legal or forensic settings, such as workplace drug screenings, paternity testing, or toxicology evaluations. In these instances, CoC proves the sample was collected correctly and that its condition remained unchanged from the patient to the laboratory.
An unbroken CoC record assures that the specimen was not substituted, contaminated, or subject to unauthorized access between collection and testing. If this documentation trail is incomplete or contains errors, the sample’s integrity is compromised, and the test results may be deemed inadmissible in court. Every individual who handles the specimen must be accountable for its security while it is in their possession.
Phlebotomist’s Role in Establishing Custody
The phlebotomist initiates the Chain of Custody process. The initial mandatory step involves verifying the patient’s identity using at least two unique identifiers, typically the full name and date of birth. Following the venipuncture, the phlebotomist must immediately and accurately label all specimen tubes in the presence of the patient.
The label must include the patient’s identifying information, the date and time of collection, and the collector’s initials. After labeling, the collection container is secured, often by placing it into a specialized kit or bag that uses tamper-evident seals or tape. The phlebotomist then completes the initial Chain of Custody form, documenting the collection details and affixing their signature to confirm the transfer of responsibility. This ensures the specimen is linked to the correct patient and is secured before it leaves the collection area.
Maintaining the Continuous Documentation Trail
Once the specimen leaves the phlebotomist’s direct care, the trail must continue, ensuring continuous chronological accountability. The transfer of the specimen to the next handler, such as a courier or a receiving laboratory technician, requires the use of a transfer log or the CoC form. Every individual who receives the specimen must sign and date the form, noting the time of the handoff.
This logging ensures the specimen is never unaccounted for and that its possession is always attributable to an authorized party. The documentation must also track storage conditions during transport, such as refrigeration or freezing, to maintain the sample’s physical integrity until it reaches the testing facility. When the sample is received at the laboratory, technicians verify the integrity of the tamper-evident seal and cross-reference the specimen label with the accompanying CoC documentation before analysis can begin.