Вот ссылка, к примеру:
http://w3.whosea.org/bct/microbio/ch19f.htm
Specimen collection
Prevention of contamination by normal vaginal, perineal and anterior uretheral flora is very vital. It is the responsibility of the laboratory to provide the patient with sterile, wide-mouthed glass or plastic, jars, beakers or other suitable receptacles which should have tight-fitting lids.
Though urine collected by suprapubic aspiration is the gold standard, it is not a practical method. Alternatively, mid-stream urine or a clean. catch urine is collected. Whenever possible, urine specimen should be collected in the morning, before the patient has voided urine.
The collection method is described as follows:
In men
Instruct the patient to wash hands.
Ask the patient to pull back the foreskin and pass a small amount of urine Holding back the fold of skin, instruct the patient to pass the remaining urine in a sterile container – this is mid-stream urine (MSU).
Place the lid, secure tightly and rapidly transport to the laboratory.If the patient is bed-ridden, the nursing staff can help the patient in the above process.
The sample is best obtained, if the procedure is properly explained to the patient.
In women
Instruct the woman to wash hands with soap and water before collection of specimen.
Patient should undress in a suitable room, spread the labia and cleanse the vulva and labia thoroughly using warm soapy water.
Rinse with warm water and dry.
Ask the patient to pass urine, discarding the first part of the stream and collecting MSU in a sterile container.
Transport the sample to the laboratory at the earliest after properly securing the lid.
Bed- ridden patients can be assisted by the nursing staff.
In Infant and young children
Ask the child to drink water or any other liquid.
Clean the external genitalia and let the child be seated in the lap of the mother/nurse/attendant.
Encourage the child to urinate and collect the same in sterile container.
Cover the container tightly and rapidly transport to the laboratory for processing.
CoIlection of urine from catheters or bag should be avoided as this does not reflect the accurate picture.
A reasonable alternative to MSU is the clean catch urine.
After periuretheral cleaning the whole urine is collected into a sterile container and then an aliquot is sent for examination.
в России моча для анализов и даже посевов собирается не в стерильные одноразовые стаканчики/контейнеры, а в майонезные (горчичные, хреновные, кетчупные и мн. пр.) баночки и о midstream/clean catch технике далеко не все врачи имеют простое и ясное представление. Нередко доктора вообще не делают посев мочи даже в необходимых случаях и поэтому вопрос чистоты/стерильности данной тары мало кого волнует. Ну а потом стерильная стандартная пластмассовая баночка для мочи стоит аж 3 рубля. А это целая проблема. Гораздо интереснее купить в больницу на 300 коек аж 2 компьютерных томографа. Откаты от баночек слишком малы наверное и главврачей по определению не интересуют. 
