Identifying non-sperm particles during flow cytometric physiological assessment: a simple approach.

Area of Science:

• Reproductive Biology
• Biotechnology
• Flow Cytometry

Background:

• Flow cytometry is increasingly used for sperm functional assessment in artificial insemination.
• Current methods using light scatter for sperm identification can lead to inaccurate counts of viable and functional sperm subpopulations.
• Accurate quantification of sperm and non-sperm particles is crucial for reliable semen evaluation.

Purpose of the Study:

• To develop a cost-efficient and accurate flow cytometric method for identifying non-sperm particles.
• To improve the precision of sperm counts and functional assessments in semen analysis.
• To address the overestimation and underestimation issues associated with light scatter-based sperm identification.

Main Methods:

• A novel flow cytometry approach leveraging sperm osmotic intolerance.
• Inducing osmotic shock by diluting sperm in water, causing membrane damage and propidium iodide (PI) staining in all sperm.
• Quantifying non-PI-positive particles via FACS analysis and using mathematical equations for accurate cell counts.

Main Results:

• The developed method accurately identifies and quantifies non-sperm particles.
• Results for non-sperm particle percentages closely matched those from SYBR14/PI and PI/CFDA staining techniques.
• The technique provides true values for sperm counts and subpopulations, overcoming light scatter limitations.

Conclusions:

• This osmotic intolerance-based flow cytometry method offers a simple, cost-efficient, and accurate way to evaluate sperm.
• It is valuable for both routine semen evaluation and specialized tests of sperm function.
• The approach enhances the reliability of artificial insemination protocols through precise sperm assessment.