title: Liquid-base cytology: a new method for oestral cycle study in Wistar's rats.
abstract: OBJECTIVE
  The objective of this study was the standardization of a collection technique and staining in liquid-base that allies the pratical and cytological wealth, making possible a larger reproductibility and microscopic easiness.
  
  
  METHODS
  Female wistar rats (n = 20) were submitted to the daily vaginal collection in saline and fastened washed (ether/alcohol) and stained in suspension with a solution of Evans Blue 0.025%. The sample was pondered by centrifugation and observed under lens of 40 x.
  
  
  RESULTS
  The stained smears allowed clear differentiation of the phases of hormonal cycle (diestrus, proestrus, estrus and metestrus); besides the differentiation of the cellular types in relation to its maturation degree having as parameters the cellular size, nucleus/cytoplasm relationship (NCR) and ink reaction. The study demonstrated the existence of three basic cellular patterns: cells with low NCR, accentuated cyanophily and small size; cells with increment in NCR, cyanophilic loss and larger volume cytoplasmatic and without nuclei keratinization cells in squamous aspect.
  
  
  CONCLUSIONS
  The staining of the material allowed, besides the cytological classification, the quantification possibility that would result in a perfected accompaniment of the cycle estrous.
authors.affiliation: Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas da UFRN/CCS Natal-RN. randmartins@yahoo.com.br
authors.forename: Rand Randall
authors.initials: RR
authors.lastname: Martins
authors.forename: Ney Moura Lemos
authors.initials: NM
authors.lastname: Pereira
authors.forename: Telma Maria Araújo
authors.initials: TM
authors.lastname: Silva
mesh_terms: D000818:Animals; D002452:Cell Count; D048429:Cell Size; D004396:Coloring Agents; D003584:Cytological Techniques / Q000379:methods / Q000592:standards; D030762:Estrous Cycle / Q000502:physiology*; D005070:Evans Blue; D005260:Female; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D014621:Vagina / Q000166:cytology*; D014626:Vaginal Smears / Q000379:methods*
chemical_list: D004396:Coloring Agents; D005070:Evans Blue