Urine Specimen Types, Collectons, and Preservations

Why do we study urine

• fluid biopsy of kidney

• non-invasive means to evaluate the kidney

• urine is ultrafiltrate of plasma

• can be used to evaluate and monitor body homeostasis and maintain metabolic disease

• can monitor effective therapy

• specimen is readily available

Specimen Collection Containers

• disposable wide-mouth, flat bottom containers with caps

• clear

• at least 50 ml capacity

• large plastic containers for 24 hr specimen

• sterile containers required for cultures

Specimen Labeling- Information

• patients name and ID number

• date and time of specimen collection 

• date of birth and ordering physician 

• label Not on lid

Specimen Labeling - Requisition Form

• must accompany specimen 

• information must match label 

• time or receipt is stamped on requisition 

• type of specimen 

• interfering medications if applicable 

What are the different specimen types

• first morning 

• random 

• timed 

Routine Voiding 

• requires no patient preparation

• collected by having patient void into container

• patient needs to assistance

• can be random or first morning 

Mid-Stream “Clean Catch”

• for bacterial cultures

• requires cleaning supplies and sterile container

• needs thorough cleansing and rinsing of genital area

• begin urination into toilet, collect midstream, finish voiding in toilet 

Catheterized specimen

• collection by medical personnel 

• sterile catheter inserted through urethra into bladder

• urine flows directly into collection bag 

• specimen obtained anytime from collection bag

• good for culture and sensitivity 

Suprapubic Aspiration

• needs medical personnel

• punctures abdominal wall and distended bladder by using needle

• sample aspirated directly from bladder

• bladder urine is normally sterile

• used for cultures or in infants 

Pediatric Collection Techniques

• plastic urine collection bags with skin adhesive 

• patients perineal area are cleaned prior to attachment 

• specimen removed as soon as possible after collection 

• specimen appropriate for routine testing

Timed Collections

• 12 or 24 hours

• may require chemical preservative to maintain integrity 

• begin and end with empty bladder

• keep refrigerated during collection 

• deliver specimen to lab immediatly after collection time period

• more accurate than random urine

Drug Specimen Collection

• proper collection, labeling, and handling must be documented

Legal Drug Specimen Collection

• chain of custody

  • documentation from time of specimen collection till time of receipt of lab results 

• specimen must withstand legal scrutiny 

  • no tampering 

Drug Specimen Collection main points

• photo ID of urine donor or ID by employer

• np unauthorized specimen 

• no adulteration or dilution of specimen

Adulteration Tests in drug specimen collection

• temp must be taken within 4 min 

  • 32.5 - 37.7 is range

• report temps outside or range immediately 

• collect another sample ASAP

• inspect urine color for anything unusual 

Specimen Rejection

• non labeled containers

• non matching labels and requisitions

• contamination of specimen

• contamination of container

• insufficient quantity 

• delayed or improper transport 

What is decreased in upreserved urine

• clarity

• glucose

• ketones

• bilirubin

• urobilinogen 

• blood cell and casts

What increases in unpreserved urine

• odor

• pH

• nitrite 

• bacteria 

How does the color change in unpreserved urine?

• it gets darker

Specimen Integrity

• test within 2 hours of collection

• most problems can be caused by bacterial growth if specimen testing is delayed 

How to preserve urine specimen

• refrigeration 

• chemical preservatives 

Refrigeration

• required for culture specimen

• causes increase specific gravity

• must return to room temp for chemical testing 

Chemical Preservatives

• commercial transport tubes

• must be compatible with chemical testing 

• idea preservative is bactericidal 

• inhibit urease and preserve formed elements