Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Cholesterol is the principal sterol synthesised by animals, an essential component of cell membranes, and precursor of steroid hormones, vitamin D and bile acids. It is also a component of lipoproteins, which are required for transport of triglycerides. Although most cells in humans are able to synthesize cholesterol, the majority is synthesized in the liver; dietary intake contributes less, although diet does influence plasma cholesterol through variation of lipoprotein production in response to the overall energy intake.
Cholesterol is transported in plasma primarily (but not exclusively) in the form of low density lipoproteins (LDL); the principal route for its removal from tissues to the liver is in high density lipoproteins (HDL), followed by excretion in the bile.
Cholesterol measurements are used to diagnose and monitor hypercholesterolaemia (monogenic, polygenic and secondary) and to assess cardiovascular risk. In risk assessment, cholesterol measurements should be considered in relation to other risk factors (e.g. cigarette smoking, hypertension, diabetes mellitus, a personal history of cardiovascular disease etc.)
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
0.5 mL blood
Minimum volume adult:
1 mL blood
Special requirements:
Unseparated sample: 3 days
Separated sample: 7 days at 15 to 25°C, 7 days at 2 to 8°C, 3 months at -20°C
Sample stability:
Unseparated: 3 days
Separated: at +15°C to +25°C – 7 Days
at +2°C to +8°C – 7 Days
Reference ranges:
Refer to NEELI guidelinesOther info:
L Cholesterol:-
Derived using the Friedewald formula (Not valid if triglyceride is greater than 4.5mmol/l)
LDL Cholesterol =Total Cholesterol-HDL Cholesterol-(Triglyceride/2.2)Non HDL Cholesterol:-
NHDL = Total Cholesterol – HDL Cholesterol