C (Frozen)   
 Send to the laboratory without delay.  Clinical history must be provided.  Citrate Samples. Samples should be double spun and separated and frozen within 4-8 hours of sample taking, if a delay is expected with transportation to the laboratory, samples must be transported as frozen.
Sample type guide
Light blue Vacutainer, Citrate anticoagulant, 4.5ml
See the Sample Requirements page for an explanation of all the sample requirements.
See the Special Instructions Legend page for a full list of special instructions.