COLLATERAL CIRCULATION VERIFICATION: Performance of a mandatory modified Allen's test on the radial artery to verify adequate ulnar collateral arterial blood supply before performing puncture.

STERILE ARTERIAL PUNCTURE: Identification and stabilization of the arterial pulse (typically radial or brachial), followed by strict surgical antisepsis and needle insertion at a precise angle using a pre-heparinized syringe.

ANAEROBIC BLOOD COLLECTION & EXPULSION: Smooth filling of the arterial blood sample without air bubbles, immediate expelling of residual microbubbles, and airtight capping to maintain anaerobic integrity.

HEMOSTASIS & HEMATOMA PREVENTION: Application of firm, direct manual pressure over the puncture site for a minimum of 5 to 10 minutes (longer for patients on anticoagulants) followed by a pressure bandage.

TEMPERATURE-CONTROLLED COLD CHAIN LOGISTICS: Immediate gentle mixing of the heparinized syringe and placement inside an ice slurry transport container to minimize cellular metabolism prior to rapid lab analysis.