During venipuncture, the correct position for the needle is bevel up at a 30-degree angle to the skin. Inserting at too steep of an angle can result in the needle being inserted too far, and this increases the risk of damage to nerves and arteries. However, if the needle is not inserted deeply enough, it may miss the vein. This may occur in patients whose veins are especially deep or in patients who are markedly obese.

Because the median cubital vein is close to the surface and located in an area least prone to nerve damage, it is the preferred site for venipuncture. The cephalic and median cephalic veins are the second choice. The basilic and median basilic veins are least preferred because of their proximity to the median nerve and brachial artery.

When the phlebotomist is taking collection tubes with blood specimens from an isolation room, the specimens should be sealed in a leak-proof plastic bag. A notice should be posted on each isolation room outlining the type of isolation and the requirements for PPE. The phlebotomist must always follow these guidelines and must enter wearing gloves, and should not take the phlebotomy tray into the room. Additionally, after the venipuncture and specimen collection is completed, all equipment except for the specimen containers must be left in the room in appropriate containers.

Asking a nurse (or anyone) to temporarily store a forensic specimen may violate the chain of custody. The phlebotomist obtaining the specimen should verify identification of the patient and clearly label the specimen, sign the chain of custody form, and place the specimen into a special transfer bag that is sealed, dated, and signed by the phlebotomist to ensure that the specimen has not been tampered with in any way.