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Commonly requested laboratory blood tests using the BD Vacutainer Tube System

Purple coloured topped bottles

Additive E.D.T.A

Tests; blood count (FBC), haemoglobin, red cell folate, glandular fever screen, glycated haemoglobin (HbA1c).

Yellow coloured topped bottles

Additive S.S.T

Tests; Biochemical Profile, Cholestrol (lipids), Amylase, Thyroid Function Test T3, T4, TSH, Uric Acid, Liver Function Test, Gamma G4, Cardiac Emzymes, Total Iron Binding Capacity (TIBC), Gamma GT, Digoxin, DNA Binding, Anticonvulsants, Autoantibodies, Hormones, Pregnancy tests (B HCG), Tumour Marker, H Pylori Antibody, Viral Antibodies, Rheumatoid Factor, PSA, Serum B12, Ferritin, Hepatitis B, Serum Theophylline.

Blue coloured topped bottles

Additive Sodium Citrate

Tests; Coagulation Studies (PT, INR)

Grey coloured topped bottles

Additive Fluoride/oxalate

Tests; Glucose, Alcohol

Pink coloured topped bottle

No additive

Tests; Blood group, Cross Match


Common blood tests and their meanings

Glucose; this is the measurement of the sugar level in the blood. Blood glucose levels are usually only a problem for patients who have diabetes.

Potassium; is an enzyme which helps to regulate the water balance and the acid base balance in the blood and tissues, but more importantly it helps to generate muscle contractions and regulate the heart beat. Potassium depletion may occur through excessive renal excretion or due to long term use of diuretics

Sodium; keeps water in the body and helps to control the blood pressure. It is regulated by the kidneys and adrenal gland. The most common cause of low sodium is due to diuretic usage.

Bicarbonate; readings will indicate whether there is too much or too little acid in the blood. Acid is a waste product of food which is normally removed by the kidneys.

Calcium; is a mineral that helps strengthen bones

Urea; is a waste product produced by the liver and secreted by the kidneys. High values may indicate that the kidneys are not working as well as they should be.

Creatinine; is a waste product largely from muscle breakdown. High values may indicate problems with the kidneys

Enzymes; are proteins which help all the chemical activities within cells to take place. Injury to the cells release these enzymes into the blood.

alkaline phosphates found primarily in the bones and the liver. High values are expected for those who are growing i.e children or when damage to bones or liver has occurred or with gallstones.

AST/ALT are also liver and muscle enzymes. They may be elevated due to liver problems such as hepatitis and excessive alcohol ingestion, muscle injury and recent heart attacks

CPK is useful for diagnosing diseases of the heart. This enzyme is the first to be elevated after a heart attack (around 3 to 4 hours).

bilirubin is a pigment removed from the blood by the liver. Elevated results are an indication of blockage of the bile duct, liver damage, erythrocyte hemolysis in the newborn as well as by the effects of certain drugs.

Albumin and globulin; measure the amount and type of protein in the blood. They are a general index of the overall health and nutritional state of an individual. Globulin is the "antibody" protein important for fighting disease.

C Reactive Protein; is a marker for inflammation. It has traditionally been used to assess inflammation in response to infection.

White Cell Count; as the name suggests, this is the amount of white cells contained in the blood. A high count can be a sign of infection, and can also be seen in certain leukemias. A low count can be a sign of bone marrow disease or an enlarged spleen

Haemaglobin (Hb); this is the amount of oxygen carrying protein contained within the red blood cells. Low Hb suggests anaemia, which can be due to nutritional deficiencies, blood loss, destruction of blood cells internally or failure to produce blood in the bone marrow. High Hb results can be due to lung disease, living at high altitudes or excessive bone marrow production of blood cells.

Platelets; these are the cells which "plug" up holes in the blood vessels to prevent bleeding. A high result can occur from premature destructive states such as immune thrombocytopenia, acute blood loss,bone marrow failure, entrapment of platelets in an enlarged spleen or the effects of some drugs such as heparin.


Normal blood ranges

Sodium                                      135-144

Potassium                                  3.3-5.3

Chloride                                    95-105

Bicarbonate                               22-31

Urea                                          2.5-6.6

Creatinine                                 55-105

Calcium                                    9; 2.20-2.60

Adjusted calcium                     2.20-2.60

Phosphate                                0.70-150

Bilirubin                                  7-23

Alkaline Phosphatase              30-125

Alanine aminotransferase        5-45

Total Protein                           62-78

Albumin                                  36-48


female 12-16

male 13.5-17.5

White cell count                      4-11

Platelets                                150-400

Neutrophils                           2.0-7.7

Cardiac enzymes                    24-195

Fasting Glucose                     3.6-6.0

Blood Gases

PH                                      7.37-7.45

Pco2                                     4.7-5.8

Bicarbonate                           21-25

Base excess                          -2 to +2

Po2                                     10.6-13.3


Clotting screen

PT                                      9.5-13.5 secs

APTT                                  22-34 secs

Thrombin time                 10.5-14 secs

D dimmer            less than 0.3mgs per lt

Fibrinogen                         1.5-4.5 gr per lt