Segregation of sperm subpopulations in normozoospermic infertile men

Figures & data

Table 1. Sperm parameters of raw semen, 50%, and 90% gradient separated semen sample.

Parameters	Original and density gradient separated sperm population
	90% (lower layer)	50% (upper layer)	Original semen	P value (Kruskal- Wallis)
Sperm count	23.80 (6.76, 64.5)	45 (34.6, 91.5)	79.2 (44.75, 120)	P < 0.05
Normal sperm morphology (%)	55 (45, 60)a	32.5 (20, 40) ^a	42 (31, 49)	P < 0.05
Reactive oxygen species (10^4RLU/min/20x10^6 sperms)	22.90 (0.92, 85.32)b	382.03 (158.30, 1409.51) ^a	4.54 (0.53, 15.15)	P < 0.05
DNA fragmentation index of sperm (%)	24.26 (22.54, 25.50)	29.93 (28.48, 31.25) ^b	27.02 (26.19, 27.76)	P < 0.05

Kruskal-Wallis test was applied to find significance between all three groups.

a: p < 0.05, b: p < 0.001 compared to 90 % lower layer by Mann-Whitney test.

Values are median and interquartile range (25%, 75%).

Figure 1.  Box plot distribution of percent high DNA staining (% HDS) cells from original semen, lower and upper gradient layers. The lower layer showed significantly (p < 0.0001) lower % HDS cells compared to upper layer. The box plot displays the 25^th percentile, median, and 75^th percentile. The circle represents outlier. The horizontal lines outside the box display minimum and maximum value.

Figure 2.  The sperm chromatin structure assay (SCSA) representative flow cytograms gated for sperm and high DNA stainability cells (HDS) from: 1) Original semen showing larger sperm population shifted towards X-axis (fragmented DNA) and 2) Density gradient separated: a) 90% layer showing less number of sperm population towards X-axis and b) 50% layer semen showing large number of sperm shifted towards X-axis.