Pathology tests database

Sample and container requirements

Acidified 24 hr Urine Plain Spot Urine acidified to pH 2 with HCl

Minimum volume required

10 mL urine

Special requirements

Store at -80°C Send by first class post . Please note nitrite positive samples will not be analysed.

Patient preparation

TMAU is associated with ingestion of certain foods, so it is important to collect this sample at the time of the odour. For this we recommend a dietary ‘Choline Load’ before sample collection using foods known to produce the odour e.g. beans, eggs, liver. Suggested Procedure: at 13:00 and 19:00 a high choline meal containing (e.g. 2 eggs + 400g baked beans or other beans – can reduce quantity for children). Then; 1. Start collecting with the first urine passed on the day after the choline load and collect urine until the end of the day i.e. empty bladder before going to bed (does not need to be a strict 24 collection). or 2. collect a single 20ml sample first thing in the morning after the choline load if 24 hr collection is impractical (e.g. in young children).

Sample viability

Turnaround time

56 days

Reference range

Please refer to report for reference ranges.

Clinical guidance

Please follow the link below to the referral laboratory website for more information: https://www.sheffieldchildrens.nhs.uk/laboratory-medicine/clinical-chemistry/metabolic-biochemistry/

Notes

Sent to Sheffield Children's Hospital