The correct answer is:

Three cc's is the ideal amount of blood for the amount of heparin in the syringe. The minimum amount of blood with which we can do gases is 1 cc. In neonatal patients where there is a need to minimize blood loss, obtain only 1 cc.

The amount of blood you send for blood gas measurements has two considerations. 

• What is the minimum amount required to perform the test comfortably 
• What is the correct proportion of heparin to blood.