Specimen Requirements

Draw blood in green-top (lithium heparin) tube AND a lavender EDTA tube.

The green-top tube is for the iPTH Chemistries (Calcium, Creatinine, and Phosphorus) and the Lavender tube is for the iPTH

The Light Green top tube must be spun and plasma separated from contact with the cells within 2 hours of collection (gel barrier is acceptable). The tube is stable at 2-8° Celsius for 48 hours. Grossly hemolyzed specimens are not acceptable. Serum is also acceptable for the chemistries (CA,CRET,PHOS), but not preferred. A morning specimen is preferred. Hemolyzed specimen is not acceptable for phosphorus. 

The Lavender top tube is used for PTH testing and may be sent unspun as whole blood. Whole blood is stable at 15-25° Celsius (room temperature) or 2-8° Celsius (refrigerated) for 24 hours. If the sample cannot be tested within 24 hours, the tube should be spun and the plasma separated and refrigerated at 2-8° Celsius. Separated plasma is stable at 2-8° Celsius for 3 days.