Certified Phlebotomy Technician Exam Study Guide 2026

Sodium citrate tubes follow blood cultures in the order of draw to avoid carryover contamination affecting coagulation tests.

The light blue (citrate) tube is used for coagulation studies including PT/INR because it preserves clotting factors.

Underfilling a citrate tube leaves excess anticoagulant relative to blood, falsely prolonging clotting times.

There is no single federal agency that directly oversees the accreditation of phlebotomists. Instead, phlebotomy accreditation and certification are typically managed by various professional organizations and certifying bodies, such as the National Phlebotomy Association (NPA), American Society for Clinical Pathology (ASCP), or National Healthcareer Association (NHA). These organizations establish standards and administer exams, rather than a federal government entity.

While visual inspection is important to identify suitable veins and rule out contraindications, palpation (the use of touch) is the most critical step in evaluating a venipuncture site. Palpation allows the phlebotomist to assess the depth, direction, size, and resilience of the vein. This helps to distinguish it from arteries or tendons and ensures a successful and safe venipuncture.

The glucose tolerance test requires specimens at exact intervals (baseline, 1-hour, 2-hour) to track the body's glucose metabolism response.