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Randomized Controlled Trial
. 2014 Jan 29:2014:154367.
doi: 10.1155/2014/154367. eCollection 2014.

Rotational dynamics of optically trapped human spermatozoa

Elavarasan Subramani  1 , Himanish Basu  2 , Shyam Thangaraju  1 , Sucheta Dandekar  3 , Deepak Mathur  2 , Koel Chaudhury  1
Affiliations
Randomized Controlled Trial

Rotational dynamics of optically trapped human spermatozoa

Elavarasan Subramani et al. ScientificWorldJournal. .

Abstract

Introduction: Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner. As sperm motility is an important criterion for assessing the male fertility potential, this technique is used to study sperm cell motility behavior and rotational dynamics.

Methods and patients: An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls.

Results: The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa. The rotational speed of sperm cells from infertile men is observed to be significantly less as compared to controls.

Conclusions: Distinguishing normal and abnormal sperm cells on the basis of beat frequency above 5.6 Hz may be an important step in modern reproductive biology to sort and select good quality spermatozoa. The application of laser-assisted technique in biology has the potential to be a valuable tool for assessment of sperm fertilization capacity for improving assisted reproductive technology.

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Figures

Figure 1
Figure 1
A schematic diagram of optical tweezer set-up used to study rotational dynamics of live spermatozoa.
Figure 2
Figure 2
(a) Rotational dynamics of normal and abnormal human sperm cells at different time points on being trapped optically (for a movie clip showing rotational motion of sperm cells under optical trap; see video in Supplementary Materials available online at http://dx.doi.org/10.1155/2014/154367). (b) Box-Whiskers plot represents the rotational speed of normal and abnormal sperm cells compared to each other.
Figure 3
Figure 3
ROC curve analysis indicates cutoff value which has high sensitivity and specificity for discrimination of (a) oligozoospermic sperm cells and controls (AUC = 0.8) (b) asthenozoospermic sperm cells and controls (AUC = 0.714). Sensitivity, specificity, and their 95% confidence of interval of (c) asthenozoospermic and (d) oligozoospermic cases plotted against the sperm rotational speed. (e) Comparison of ROC curves of oligozoospermic and asthenozoospermic cases.
Figure 4
Figure 4
(a) Correlation of sperm swimming speed and rotational speed (beat frequency) of normal and abnormal sperm cells. (b) Measurement and comparison of normal and abnormal spermatozoa swimming speed before and after optical trapping. *P < 0.05, **P < 0.001.
See this image and copyright information in PMC

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