From experience, the high sensitivity associated with modern testing at RML has resulted in a proper collection of the specimen to maintain the integrity of the specimen. Some tests require serum, plasma, or blood for testing. From my experience, I know for sure that the order of draw is as follows; Blood culture; Blue tube to ensure coagulation (i.e. sodium citrate); Red (no gel); Gold SST; Green and Dark Green (Heparin, with/without gel); Lavender (EDTA); Pink – blood bank (i.e. EDTA); Gray (Fluoride/Oxalate).
If I’m perhaps right, you inquire to know which tube color in the order of draw comes first; according to the order, excluding the blood culture factor, the Blue tube, which ensures coagulation comes first. Although many make the mistake of placing these tubes wrongly as such result in compromised test results and baseless conclusions.