[Single- and two-layer gradient centrifugation in sperm separation: comparison and appraisal].
OBJECTIVE
To appraise the effect of single- and two-layer Percoll density gradient centrifugation in sperm separation.


METHODS
Twenty semen specimens underwent single-(50%) and two-layer (90% and 45%) density gradient centrifugation, respectively. The sperm class analyzer (SCA) was used to analyze sperm density, motility and dynamic parameters and round cell density before and after the treatment.


RESULTS
After separation, the sperm recovery rate of the single-layer method was (65.5 +/- 12.8)%, significantly higher than that of the two-layer method (P < 0.01). The percentages of grade a sperm of the single- and two-layer method were significantly higher than pre-treatment (P < 0.05, P < 0.01), that of the single-layer was significantly lower than that of the two-layer method (P < 0.05), but the percentage of grade c sperm of the former was significantly higher than that of the latter (P < 0.05). Compared with pre-treatment, the percentage of grade a + b sperm of the two-layer method was significantly higher (P < 0.05), while that of the single-layer method showed no significant difference (P > 0.05), and the round cell density of both the methods was significantly lower (P < 0.05, P < 0.01), with no significant differences between the two methods (P > 0.05).


CONCLUSIONS
The single-layer method yields a higher rate of sperm recovery and causes little change in the sperm motility, while the two-layer method effects a lower rate and significantly improves sperm motility. Both the methods can efficiently separate sperm from round cells, and each has its own advantages and its application value in in vitro treatment of sperm.
Zhou
Qi-zhao
QZ
Department of Urology, Nanfang Hospital, China.
Feng
Chun-qiong
CQ
Zou
Ya-guang
YG
Shu
Wen
W
Li
Tie-qiu
TQ
Li
Fei
F
Liu
Cun-dong
CD
Mao
Xiang-ming
XM
D002469:Cell Separation / Q000379:methods; D002499:Centrifugation, Density Gradient / Q000379:methods*; D006801:Humans; D008297:Male; D011205:Povidone; D012822:Silicon Dioxide; D013076:Sperm Count / Q000379:methods*; D013094:Spermatozoa / Q000166:cytology*
C016039:Percoll; D012822:Silicon Dioxide; D011205:Povidone