Room temperature samples Samples collected in EDTA (lavender top) tube Samples collected in sodium or lithium heparin (green top) tube Samples received with any plasma remaining on cells Frozen samples Samples collected in tan top tube
Reference Range(s)
794-1470 MCG/DL
Specimen Requirements
Preferred Specimen
EDTA (royal blue top) trace metal-free tube
Minimum Volume
0.3 mL red blood cells
Sample Stability
Unacceptable room temperature 30 days refrigerated Unacceptable frozen
Transport Temperature
Critical Refrigerated
Collection Instructions
Collect 7 mL whole blood in a royal blue trace metal-free tube with EDTA. Centrifuge sample within 2 hours of collection. Remove all plasma and discard. It is important that all plasma be removed from the cells, as leaving any plasma on the cells may cause the sample to be rejected. Submit remaining red blood cells in the original collection tube. Clearly label tube as rbcs. Critical refrigerate (CRF). Note: this test is designated for exposure monitoring/investigation.