Biochemistry Department Information
Blood sample requirements
Relevant clinical details on the request form help result authorising and decisions on contacting the clinician.
Most combinations of the following common tests can be done on one heparin tube (green top). Immediately after filling the heparin tube, mix gently by inversion 8 – 10 times.
| Antibiotics
(Gentamicin, Tobramycin, Vancomycin) |
Fertility Hormones
(FSH, LH, Oestradiol, Prolactin, Progesterone) |
Liver Function Tests
(ALB, ALP, ALT, AST, TBil) |
Rheumatoid Factor * | |
| Albumin | CK | GGT | LDH | Salicylate |
| βHCG | Cortisol | Glucose | Magnesium | Thyroid Tests
(TSH, FT3, FT4) |
| Bilirubin
(Total, Direct) |
CRP | Immunoglobulins | Osmolality | Total Protein |
| B12 & Folate | Therapeutic Drugs
(Digoxin, Lithium *, Phenytoin, Carbamezapine, Valproate, Theophyliine) |
Iron Studies
(Iron, Transferrin, Ferritin) |
Paracetamol | Troponin I |
| Calcium | Electrolytes
(Na, K, Cl) |
Lipase | Phosphate | Urea |
| BNP (NT-proBNP) | Ethanol | Lipids
(Cholesterol, HDL, Triglycerides) |
Tumour Markers
(AFP, βHCG, CA125, CA153, CA199, PSA) |
Uric Acid |
NOTE:
1. BNP, HbA1c and PTH require EDTA blood (purple top). Separate tube from FBC please.
2. Lactate is performed on VBG or ABG samples.
3. * Lithium or Rheumatoid Factor requires serum (red top).
Specialised tests are sent away to Canterbury Health Laboratories (CHL) and access to CHL Test Guide Manager is recommended for guidance on sample type, volume, condition of collect, type of assay etc.
Blood gases
Immediately after taking sample, expel any air from the syringe and mix gently by inversion 8 to 10 times. Label syringe. Pre-printed labels are acceptable on blood gas samples.
Cord gases need to be labelled with the Mother’s details (Mother’s name, NHI and/or date of birth), and NOT the baby’s details. The Mother’s pre-printed labels are acceptable, indicate if the sample is Arterial or Venous on this label.
Paediatric samples
On children or difficult collects, we will be happy to give you the minimum sample requirement for the tests you would like to request. Phone Ext 2448.
It is helpful if you indicate on the form which tests are a priority when it is difficult to meet minimum blood volumes for all the tests requested. For maximum recovery of serum, please collect sample in a plastic Microtainer. Paediatric samples can be labelled with pre-printed labels.
Haemolysed Blood samples
Haemolysis affects most biochemistry tests to some degree. The tests most seriously affected are:
· Falsely increased: potassium, magnesium, urate, iron, phosphate, total protein, AST, LD, folate.
· Falsely decreased: bilirubin, GGT. BNP is not performed on haemolysed samples.
The most common cause of haemolysis is forcing blood from a syringe into a blood tube through the needle. It is best to remove the needle from the syringe, and the stopper from the tube, and expel the blood gently down the wall of the tube.
Lipaemic Blood samples
The analyser compensates fairly well for mild lipaemia. Moderate to gross lipaemia affects all tests to some degree. A fasting sample the next morning will resolve the interference for most patients.
Key contacts
Biochemistry Laboratory: Phone 06 878 1308 Ext 2448
Head of Department: Tim Aitken 06 878 1308 Ext 2449