title: Addition of eosin to the aniline blue assay to enhance detection of immature sperm histones.
abstract: OBJECTIVE
  To compare the aniline blue assay with and without eosin, and to correlate the results with pregnancy outcome after intracytoplasmic sperm injection (ICSI) procedure.
  
  
  METHODS
  A retrospective study.
  
  
  METHODS
  University-based fertility center.
  
  
  METHODS
  One hundred thirty infertile patients.
  
  
  METHODS
  Left-over washed sperm after each ICSI procedure were fixed on glass slides and stained with aniline blue with and without eosin.
  
  
  METHODS
  Chromatin condensation, pregnancy, and age.
  
  
  RESULTS
  Percentage chromatin condensation assessed by aniline blue-eosin was higher compared with standard aniline blue (72.4 +/- 2.4% vs. 64.0 +/- 2.4% [mean +/- SEM]). Chromatin condensation was higher in pregnant (86.6 +/- 0.9%) versus nonpregnant (80.9 +/- 2.1%) women age 35 years or more. In younger women, chromatin condensation was not correlated with pregnancy outcome. There was no correlation between chromatin condensation and ICSI fertilization or male age.
  
  
  CONCLUSIONS
  Adding eosin counterstain to aniline blue improved assessment of chromatin condensation, suggesting that the standard assay underestimated chromatin condensation. The association between chromatin condensation and pregnancy in older but not younger women suggests that oocytes of younger women had the capacity to compensate for the immature sperm shortcomings.
authors.affiliation: Department of Gynecology and Obstetrics, Loma Linda University School of Medicine, Loma Linda, California 92354, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wong
authors.forename: Sandra S
authors.initials: SS
authors.lastname: Chuan
authors.forename: William C
authors.initials: WC
authors.lastname: Patton
authors.forename: John D
authors.initials: JD
authors.lastname: Jacobson
authors.forename: Johannah
authors.initials: J
authors.lastname: Corselli
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Chan
mesh_terms: D000328:Adult; D000367:Age Factors; D000814:Aniline Compounds; D042002:Chromatin Assembly and Disassembly; D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D005260:Female; D006657:Histones / Q000032:analysis*; D006801:Humans; D007246:Infertility / Q000235:genetics / Q000628:therapy*; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000737:chemistry*; D013194:Staining and Labeling / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D000814:Aniline Compounds; D004396:Coloring Agents; D006657:Histones; C017006:aniline blue; D004801:Eosine Yellowish-(YS)