title: Stability of urine specimens stored with and without preservatives at room temperature and on ice prior to urinalysis.
abstract: OBJECTIVE
  Laboratories determine the most appropriate approach for the collection and transport of urine specimens. We investigated the effect of a chlorhexidine-based preservative tube on sample stability, compared the results of refrigerated polystyrene tubes with no additives, and investigated the effect of temperature on the performance of preservative tubes.
  
  
  METHODS
  Fresh urine specimen (n=48) aliquots in BD Vacutainer® Plus Urinalysis Preservative Tubes and polystyrene tubes were analyzed on an Iris Diagnostics iQ200. Samples in polystyrene tubes were refrigerated for 4 and 8h. Four aliquots in preservative tubes were kept at room temperature for 4, 8, 24, and 72h, while two aliquots were kept on ice for 4 and 8h.
  
  
  RESULTS
  There was good agreement for all chemistry and microscopy parameters with the exceptions of white blood cells (WBCs) at 24 and 72h and red blood cells (RBCs) at 72h. Preservative tubes on ice showed a significant decrease in concordance of WBCs and calcium oxalate (CaOx) parameters compared with the results at room temperature. Results of refrigerated polystyrene tubes showed good agreement with the exceptions of WBC clumps and amorphous crystal at 8h.
  
  
  CONCLUSIONS
  A chlorhexidine-containing preservative tube seems advantageous for urine sample transport from outside healthcare services. A preservative tube offers comparable results with urine samples kept in a refrigerator for 4-8h for the majority of parameters. Keeping samples at room temperature is recommended when preservative tubes are used because ice produces a negative effect on WBCs and CaOx.
authors.affiliation: Department of Biochemistry, Public Health Laboratory, Aydın, Turkey.
authors.forename: Müjgan
authors.initials: M
authors.lastname: Ercan
authors.affiliation: Türkiye Yüksek İhtisas Education and Research Hospital, Clinical Biochemistry, Ankara, Turkey.
authors.forename: Emiş Deniz
authors.initials: ED
authors.lastname: Akbulut
authors.affiliation: Selçuk University, Faculty of Medicine, Department of Biochemistry, Konya, Turkey.
authors.forename: Sedat
authors.initials: S
authors.lastname: Abuşoğlu
authors.affiliation: Ankara Numune Education and Research Hospital, Clinical Biochemistry, Ankara, Turkey. Electronic address: fatmamericyilmaz@hotmail.com.
authors.forename: Fatma Meriç
authors.initials: FM
authors.lastname: Yılmaz
authors.affiliation: Ankara Numune Education and Research Hospital, Clinical Biochemistry, Ankara, Turkey.
authors.forename: Esra Fırat
authors.initials: EF
authors.lastname: Oğuz
authors.affiliation: Ankara Numune Education and Research Hospital, Clinical Biochemistry, Ankara, Turkey.
authors.forename: Canan
authors.initials: C
authors.lastname: Topçuoğlu
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Urology, Ankara, Turkey.
authors.forename: Volkan
authors.initials: V
authors.lastname: Öztekin
authors.affiliation: Ankara Numune Education and Research Hospital, Clinical Biochemistry, Ankara, Turkey.
authors.forename: Nihal
authors.initials: N
authors.lastname: Boğdaycıoğlu
mesh_terms: D015925:Cryopreservation; D006801:Humans; D007053:Ice; D011310:Preservatives, Pharmaceutical / Q000494:pharmacology*; D012034:Refrigeration; D013048:Specimen Handling / Q000379:methods*; D013696:Temperature; D016482:Urinalysis / Q000379:methods*
chemical_list: D007053:Ice; D011310:Preservatives, Pharmaceutical
keywords: Preanalytic phase; Preservative tube; Urinalysis