Urines for routine microscopy culture and sensitivity

The Microscopy method used in the laboratory uses an analyser to estimate the number of white and red blood cells, and the number of bacteria in urine to help to distinguish infection from contamination. If there is evidence of infection then a culture and sensitivity will be performed.

The containers used for urine microscopy and culture are changing Click on the links below for more information.

BHNFT Boric Acid Urine Monovette – points to remember

SARSTEDT Boric Acid Instructions for Use

A midstream urine (MSU) or catheter specimen should be sent to the laboratory in a Sarstedt Monovette tube. These tubes contain boric acid so should be filled to the marked line otherwise results may be unreliable and the sample may be rejected.  Universal containers will continue to be accepted for a further few months, however urines received in inappropriate unsterile containers will not be processed.
Please note red topped universals containing boric acid must be at least half full (10mls) of urine, samples received containing less than this will be rejected due to the fact that unreliable results may be obtained as Boric acid can affect the viability of the organisms if in too high a concentration. If only a small sample can be obtained from the patient a white toped container should be used but sent to the lab ASAP.

Urines should be received within 1-2 hours of collection. If this is not possible then refrigeration at 4°C for up to 24 hours is possible for most specimens without much change in bacterial count, but the white cells may become unrecognisable.

Red blood cells may lyse in dilute urine shortly after the specimen being taken, an on-site “stick” test may give a more accurate indication of the presence of blood.

Suggestions for the collection of a mid-stream urine (MSU) sample

Males

Retract the foreskin if necessary, and then pass the first part of the urine stream into the w.c. pan and catch the second part into a sterile universal container.

Females

If there is a menstrual or vaginal discharge, use of a vaginal tampon is helpful. The patient should be instructed to clean the vulva from the front backwards using a cotton-wool swab soaked in sterile water, whilst separating the labia with two fingers of one hand. Antiseptics must be avoided. Keeping the labia separate, the patient passes the first part of the urine stream into the w.c. and catches the second part into a sterile universal container.

Babies and young children

A clean-catch specimen is preferred because urine in adhesive bags is frequently contaminated.

 

For further information please refer to the NHS Choices website using the following link: NHS Choices- How Should I Collect and Store a Urine Sample?

 

Urine for TB culture

Three complete consecutive early morning specimens are usually required. These may be refrigerated each day and taken to the laboratory together – the laboratory can supply suitable containers.

Urine for Legionella and Strep pneumoniae antigen testing

Urine samples should be collected in the normal way into a white topped plain sterile universal container, they can be kept at room temperature for up to 24 hours, but ideally should be sent to the laboratory as soon as possible. Alternatively they can be stored at 2-8 C in a refrigerator.

Urine for Ova, cysts and parasite testing (Schistosoma)

In urinary schistosomiasis, very few ova are present in the urine. The number of ova in the urine varies throughout the day, being highest in urine obtained between 10am and 2pm. In patients with haematuria, eggs may be found trapped in the blood and mucus in the terminal portion of the urine specimen. It is therefore preferable to obtain total urine collected over the time period between 10am and 2pm. Alternatively, a 24hr collection of terminal samples of urine may be helpful. Sterile containers without boric acid must be used ( White topped Universal).