title: Hematologic reference intervals for Xenopus tropicalis with partial use of automatic counting methods and reliability of long-term stored samples.
abstract: BACKGROUND
  The African frog, Xenopus tropicalis, is widely used in biomedical and toxicologic research. Reference intervals (RI) for hematologic variables, valuable to research and health status assessment, have not been established.
  
  
  OBJECTIVE
  The purpose of the study was to determine hematologic RI of X tropicalis, and establish whether automated cell counting can facilitate routine hematologic assessment in frogs.
  
  
  METHODS
  Blood from 41 adult healthy X tropicalis was collected via cardiac puncture, and diluted in Natt-Herrick solution. Complete WBC, RBC, and thrombocyte counts (hemocytometry), differential WBC counts (Wright-Giemsa-stained smears), PCV (centrifugation), total protein (refractometry), and automated total cell counts (WBC + RBC + thrombocytes, Sysmex particle counting) were determined. Concordance correlation coefficients calculated the agreement between total cell counts obtained by hemocytometry and automated particle counting, and between total cell counts at collection and after 2 years of storage.
  
  
  RESULTS
  Leukocyte morphology was similar to other amphibians and mammals. PCV was similar to other frogs; RBC counts were higher, and MCV was lower than in other frog species. Neutrophils were the most numerous WBC. Agreement was good between hemocytometry and automated cell counts. Subtracting the hemocytometer WBC and thrombocyte counts from the automated total cell count reliably yielded the RBC count. Cellular integrity evaluated 2 years post collection was good, and automated counts were not clinically different from counts at collection.
  
  
  CONCLUSIONS
  We provide hematologic RI for X tropicalis, suggest how automated cell counts may facilitate hematologic assessments of frogs, and establish that blood in Natt-Herrick solution is stable 2 years post collection.
authors.affiliation: Department of Biology, University of Prince Edward Island, Charlottetown, PE, Canada.
authors.forename: Lily A
authors.initials: LA
authors.lastname: Maxham
authors.affiliation: Canadian Wildlife Health Cooperative, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.|Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.
authors.forename: María J
authors.initials: MJ
authors.lastname: Forzán
authors.affiliation: Department of Biology, University of Prince Edward Island, Charlottetown, PE, Canada.
authors.forename: Natacha S
authors.initials: NS
authors.lastname: Hogan
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.
authors.forename: Raphaël V
authors.initials: RV
authors.lastname: Vanderstichel
authors.affiliation: Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.
authors.forename: Cornelia V
authors.initials: CV
authors.lastname: Gilroy
mesh_terms: D000818:Animals; D001772:Blood Cell Count / Q000379:methods / Q000662:veterinary*; D001793:Blood Preservation / Q000662:veterinary; D005260:Female; D005434:Flow Cytometry / Q000379:methods / Q000662:veterinary; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results; D013997:Time Factors; D014981:Xenopus / Q000097:blood*
keywords: Automated counts; Xenopus tropicalis; blood; long-term storage; reference intervals