title: [Influence of the pre-analytical specimen storage conditions on the fecal occult blood test results].
abstract: BACKGROUND
  Korean national cancer screening program selected fecal occult blood test (FOBT) as a primary screening method of colorectal carcinoma in adult > or =50 yr old irrespective of symptom. Notice to pre-analytical errors is especially important for the FOBT because examinees collect and submit their specimens to laboratories by themselves. We examined the influences of the fecal storage temperatures, durations and with or without buffer on the FOBT results.
  
  
  METHODS
  Thirty FOBT-positive specimens above 100 ng/mL were used for the study from July to August 2008. Quantitative FOBT was performed with OC-sensors II (Eiken Chemical Co., Japan). Each specimen was divided into 4 groups. Two groups in plastic buffer-free containers were kept either at 4 degrees C or room temperature (25-28 degrees C), respectively. Another two groups in buffer-tubes were also kept either at 4 degrees C or room temperature. Each group was repeatedly examined with same method every 24 hr up to 120 hr.
  
  
  RESULTS
  Eleven specimens (36.7%) in buffer-free containers converted to negative results (below the 100 ng/mL) after 24 hr and 17 specimens (56.7%) did after 48 hr at room temperature. Ten specimens (33.3%) in buffer-free containers converted to negative after 48 hr at 4 degrees C. Specimens contained in buffer-tubes showed little change; 3 specimens (10.0%) at room temperature and no specimen at 4 degrees C showed negative conversions after 48 hr.
  
  
  CONCLUSIONS
  Buffer-tube minimizes false negative FOBT results during pre-analytical delay of specimen. The examinees using buffer-free containers need to be educated to hand in their specimens to laboratories as soon as possible.
authors: Department of Laboratory Medicine, Sanggye Paik Hospital, Inje University College of Medicine, Nowon-Gu, Seoul, Korea.
authors: Soo Jin
authors: SJ
authors: Yoo
authors: Se Jin
authors: SJ
authors: Moon
authors: Eun Hye
authors: EH
authors: Gwack
authors: Bo Moon
authors: BM
authors: Shin
mesh_terms: D002021:Buffers; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009780:Occult Blood; D013048:Specimen Handling; D013696:Temperature; D013997:Time Factors
chemical_list: D002021:Buffers