Addition of eosin to the aniline blue assay to enhance detection of immature sperm histones.
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.
Wong
Alexander
A
Department of Gynecology and Obstetrics, Loma Linda University School of Medicine, Loma Linda, California 92354, USA.
Chuan
Sandra S
SS
Patton
William C
WC
Jacobson
John D
JD
Corselli
Johannah
J
Chan
Philip J
PJ
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
D000814:Aniline Compounds; D004396:Coloring Agents; D006657:Histones; C017006:aniline blue; D004801:Eosine Yellowish-(YS)