A novel sorting technology allows for highly efficient selection of sperm without chromatin damage

Area of Science:

• Reproductive Biology
• Cell Biology
• Biotechnology

Background:

• Sperm chromatin damage is linked to male infertility, miscarriage, and poor embryo development.
• Current detection methods damage sperm, rendering them unusable for clinical applications.
• Early apoptosis increases sperm membrane permeability, allowing ion entry and chromatin damage.

Purpose of the Study:

• To introduce a new method for selecting sperm with intact chromatin using fluorescence-activated cell sorting (FACS).
• To utilize a proprietary fluorochrome (PF-1) for negative selection of undamaged sperm.
• To assess the efficacy and impact of PF-1 sorting on sperm quality.

Main Methods:

• Sperm were stained with proprietary fluorochrome (PF-1), a large fluorescent organic cation.
• Fluorescence-activated cell sorting (FACS) was used for negative selection of PF-1-negative sperm (undamaged).
• Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay verified sorting accuracy.

Main Results:

• PF-1 sorting significantly reduced TUNEL-positive sperm from 19.5% in the positive fraction to 1.5% in the negative fraction (p < 0.00001).
• Post-sorting motility and vitality were 49.4% and 65.0%, respectively.
• The PF-1 sorting method effectively removed TUNEL-positive sperm with minimal impact on viability.

Conclusions:

• Proprietary fluorochrome (PF-1) activated sperm sorting offers a viable method to eliminate TUNEL-positive sperm.
• This technique may provide a therapeutic option for male infertility associated with high levels of sperm DNA damage.
• Further research is required to confirm if PF-1 sorting improves in vitro fertilization (IVF) outcomes.