Your co-worker, Jayson Clarke, has just performed a phleboto…

Your co-worker, Jayson Clarke, has just performed a phlebotomy on a patient. He was trying to completely fill a 4.5 mL EDTA Vacutainer tube (purple top) with blood. He was only able to fill the tube 1/3 the way with blood and wants to know if this sample is acceptable for a magnesium assay. Which is the most correct answer to tell him?