title: Can sex be determined from a blood smear?
abstract: OBJECTIVE
  Originally, this blind study was designed to check whether blood smears constitute reliable tools to determine sex. However, when we analyzed our data some interesting findings immerged and in this paper we try to highlight them.
  
  
  METHODS
  74 blood smears (35 women and 39 men) have been performed and then stained. 200 polynuclearneutrophils were examined for nuclear appendages and classified into four groups: neutrophils with form A, B or C appendages and neutrophils without any appendage.The difference (A-C) was calculated for each slide. The "cytologic sex" was defined as a male in case of a negative value and as a female otherwise.
  
  
  RESULTS
  Neutrophils bear the same amount of appendages in both genders (p=0.37). But the number of form A is greater in females (p<0.0001) and form C is much more frequent in males (p<0.0001), that is why, the difference A-C is the best way to differentiate between both sexes.The distribution histogram of A-C in women shows a multimodal histogram contrary to men's graphwhich is a bell-shaped curve. The menstrual cycle was incriminated in this feature.
  
  
  CONCLUSIONS
  Blood smear is a reliable tool to determine gender.
  
  
  BACKGROUND
  None declared.
authors.affiliation: EHU "1er Novembre 1954" - Hemobiology, Oran, Algeria.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Brahimi
authors.affiliation: EHU "1er Novembre 1954" - Hemobiology, Oran, Algeria.
authors.forename: Affaf
authors.initials: A
authors.lastname: Adda
authors.affiliation: EHU "1er Novembre 1954" - Hemobiology, Oran, Algeria.
authors.forename: Hassiba
authors.initials: H
authors.lastname: Lazreg
authors.affiliation: EHU "1er Novembre 1954" - Hematology and Cell Therapy, Oran, Algeria.
authors.forename: Hadjer
authors.initials: H
authors.lastname: Beliali
authors.affiliation: EHU "1er Novembre 1954" - Hematology and Cell Therapy, Oran, Algeria.
authors.forename: Soufi
authors.initials: S
authors.lastname: Osmani
authors.affiliation: EHU "1er Novembre 1954" - Hematology and Cell Therapy, Oran, Algeria.
authors.forename: Mohamed Amine
authors.initials: MA
authors.lastname: Bekadja
keywords: Blood Smear; May-Grünwald-Giemsa stain; Nuclear appendages; Polymorphonuclear neutrophils; gender