Pathology Handbook

Homocysteine (for thrombotic tendency)

Clinical Indications

  • Premature cardiovascular disease
  • Thrombotic tendency
  • Possible B12/folate deficiency

Request Form

Request on ICE


Analysed by referral laboratory if specific criteria met.

Specific Criteria

Agreed with Consultant Biochemist.

Patient Preparation

Patient should be fasting as homocysteine levels may increase after food.

Turnaround Time

3 weeks


EDTA Plasma in lemon-top tube


2 ml minimum


Vacutainer lemon top


Sample must be transported to laboratory and separated within 30 minutes of collection

Patients must be bled at Southend Hospital.

Lab Handling

Sent to referral laboratory (Guy's Hospital)

Causes for Rejection

Unlabelled or inadequately labelled sample.

Delay in transit to laboratory.

Reference Range

Less than 17 mmol/l 

Raised levels may indicate a genetic disorder or sulphur amino acid metabolism and/or B12/folate deficiency. Raised levels are reported to be a risk factor for premature cardiovascular disease and/or clotting tendency.