title: Detection of apoptosis in colorectal carcinoma by light microscopy and in situ end labelling.
abstract: OBJECTIVE
  An in situ end labelling reaction (ISEL) was recently described for the detection of apoptotic cells in histologic sections. We compared the efficiency and reproducibility of this assay with those of routine light microscopy using hematoxylin and eosin (H&E) in the quantitation of apoptotic cells in colorectal cancer.
  
  
  METHODS
  Paraffin-embedded archival tissues from 15 colorectal carcinomas were used in the study. ISEL was performed using terminal deoxynucleotidyl transferase, biotinylated deoxyuridine triphosphate and streptavidin-alkaline phosphatase.
  
  
  RESULTS
  Apoptotic indices determined by the two assays showed a strong positive correlation (Pearson coefficient 0.82), with the ISEL assay detecting twice the number of apoptotic cells as that seen with H&E staining. Both assays showed significant interobserver and intraobserver variation, while the ISEL assay also showed considerable interassay variability and was less cost-effective than H&E in the detection of apoptotic cells.
  
  
  CONCLUSIONS
  In the light microscopic quantitation of apoptosis in colorectal tumors, the ISEL assay offered no greater reproducibility, and was less cost-effective, than routine H&E staining.
authors.affiliation: School of Pathology, University of New South Wales, Sydney, Australia.
authors.forename: N J
authors.initials: NJ
authors.lastname: Hawkins
authors.forename: J
authors.initials: J
authors.lastname: Lees
authors.forename: R L
authors.initials: RL
authors.lastname: Ward
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D053938:DNA Fragmentation; D004253:DNA Nucleotidylexotransferase; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin; D006801:Humans; D008853:Microscopy; D015588:Observer Variation
chemical_list: D004253:DNA Nucleotidylexotransferase; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin