We found that, although sodium chloride raised mean arterial blood pressure in the salt-sensitive subjects (p less than 0.005), sodium citrate did not. However, under both sodium salts pressor response to norepinephrine and angiotensin II was significantly greater than under placebo (p less than 0.02).
Tube inversions ensure mixing of anticoagulant (heparin) with blood to prevent clotting. Gray. Gray. • Potassium oxalate/ sodium fluoride.
Sodium citrate is used to prevent donated blood from clotting in storage. It is also used in a laboratory, before an operation, to determine whether a person's blood is too thick and might cause a blood clot, or if the blood is too thin to safely operate.
The Sediplast Westergren and Streck methods use citrate as an anticoagulant, which results in dilution of blood and should correct the ESR owing to higher hematocrit values. The same study also proved the stability of refrigerated EDTA blood samples for 24 hours.
Anticoagulants are used to prevent clot formation both in vitro and in vivo. Historically, EDTA has been recommended as the anticoagulant of choice for hematological testing because it allows the best preservation of cellular components and morphology of blood cells.
The tests each bottle is used for are the same: the purple one is for cell count, the yellow one is for electrolytes, albumin and LDH, the grey one is for glucose, and blood culture bottles can be used for fluid cultures.
EDTA is the anticoagulant of choice for blood collection for DNA extractions because it inhibits DNase activity and does not change the quantity of DNA. In other words, sodium heparin, an anticoagulant used widely for blood collection, has been known to inhibit DNA polymerase activity in PCR assays (2).
Cause: Citrate is the anticoagulant used in blood products. It is usually rapidly metabolised by the liver. Rapid administration of large quantities of stored blood may cause hypocalcaemia and hypomagnesaemia when citrate binds calcium and magnesium. This can result in myocardial depression or coagulopathy.
ORDER OF DRAW
- First - blood culture bottle or tube (yellow or yellow-black top)
- Second - coagulation tube (light blue top). If just a routine coagulation assay is the only test ordered, then a single light blue top tube may be drawn.
- Third - non-additive tube (red top)
- Last draw - additive tubes in this order:
Collection Tubes for Blood Specimens
| Yellow Stopper Tube: (two types) Solution A or Solution B |
|---|
| Additive: | ACD, Solution A |
|---|
| Inversions: | 8 |
| Laboratory Use: | Tissue typing and some Red Cross testing. Refer to specific test for proper tube. |
| Additive: | ACD, Solution B |
The waste tube must also be a light-blue top tube or a tube that contains no additives. This waste tube is drawn first to remove the air in the tubing of the winged collection device. Once blood flows through the tubing, the waste tube can be removed and discarded. The waste tube does not need to be completely filled.
Gold-top serum separator tube (SST)This tube contains a clot activator and serum gel separator – used for various chemistry, serology, and immunology tests. If the specimen requirement for a test is red-top tube(s), do not use gold-top/SST tube(s).
Background: Sodium citrate has been used as an anticoagulant to stabilize blood and blood products for over 100 years, presumably by sequestering Ca(++) ions in vitro. Subsequent experiments showed that calcium citrate itself impairs coagulation dynamics.
PHLEBOTOMY SERVICES
| STOPPER COLOR | CONTENTS | VOL. |
|---|
| Red | No additive | 7.0 mL |
| Light Blue | 3.2% Sodium Citrate | 4.5 mL |
| Gold Top (Serum Separator, "SST") | Contains separating gel and clot activator | 6.0 mL |
| Light Blue - Yellow Label on Tube | Thrombin | 2.0 mL |
Clinical laboratories often receive extra blood tubes beyond what is needed for associated laboratory test orders. Sometimes, this practice involves drawing tubes of every possible color (the “rainbow”) to allow for add-on testing at a later time.
Order of draw is essential in avoiding cross contamination from additives of one tube to the next. Cross contamination, depending on the tests ordered, could cause seriously erroneous results, improper patient treatment and possibly death. While most blood collections (straight venipuncture vs.
The reasoning behind the NCCLS order of draw is that the red plastic tubes contain a clot activator, which could interfere with coagulation testing if drawn before the sodium citrate tube.
Serum is usually collected in mottled red/gray, gold, or cherry red-top tubes, and red-top tubes are occasionally used. Plasma is obtained from blood that has been mixed with an anticoagulant in the collection tube and has, therefore, not clotted.
EDTA (Purple)Plasma stored from EDTA blood can also be used to measure most proteins, and genetic material can easily be stored from EDTA buffy coats (the interface between the red cells and the plasma after centrifugation, containing white cells and platelets).
A key difference between plasma and serum is that plasma is liquid, and serum is fluid. Serum is mostly used for blood typing but is also used for diagnostic testing. Plasma, on the other hand, is mostly used for blood-clotting related problems.
Whole blood samples should not remain at room temperature longer than 8 hours. If assays are not completed within 8 hours, samples should be stored at +2°C to +8°C no longer than 7 days. If assays are not completed within 7 days, or the sample is to be stored beyond 7 days, samples should be frozen at -15°C to -20°C.
SST tubes contain spray-coated silica and a polymer gel for serum separation. They use for serum determinations in chemistry, serology, immunology and HIV tests [1]. Serum separator gel that is located at end of the tube plays the role of a stable chemical and physical barrier between serum and blood clot [7].
Serum Separator Tube (SST®) for serum determinations in chemistry and serology. Contains separator gel and should not be used for toxicology or drug testing. Inversions ensure mixing of clot activator with blood. Blood clotting time 30 minutes.
Heparin injection is an anticoagulant. It is used to decrease the clotting ability of the blood and help prevent harmful clots from forming in blood vessels.
