A group of Spanish researchers from Autonomous University of Barcelona found that by photo-stimulating boar sperm with red LED lights through a 30 minute cycle could improve in vitro sperm fertilization performance, according to a paper the team submitted to Nature.

In general, the quality of sperms that are incubated at 37 °C for 90 minutes tends to decrease over time, the red LED photo-stimulating procedure, though, was able to prevent this natural deterioration.

The team led by Marc Yeste subjected commercially prepared boar sperm to red LEDs capable of emitting wavelengths ranging from 620 nm–630 nm. The lights were controlled with a software.

They found single period light exposure lasting from 5 to 10 minutes was unable to improve boar sperm quality, but the team found sperm mobility improved significantly by adjusting the exposure period to three 10-minute cycles.

The most effective photo-stimulating cycle was exposing the red LED lights for 10 minutes followed by 10 minute dark phase, and put under red LED lights for another 10 minutes (10-10-10).

Previous studies used red lasers to stimulate mouse sperm found a connection between photo-stimulation with mitochondria activation in sperms. The Spanish team chose red LEDs over laser technology because it was less costly, while retaining the lighting intensity and stability found in lasers.

Findings from the Spanish team research could be applied to improve fertility rates in humans receiving in vitro treatment, reported Science.mic.