Time-resolved fluorescence microscopy (FLIM)

2023: Russia has developed a new method for selecting viable sperm for IVF. It is based on FLIM

In early July 2023, specialists from Sechenov University announced the creation of a new method for selecting the highest quality and viable sperm. This is time-resolved fluorescence microscopy (FLIM).

This method, as explained in the university, allows without the use of contrast agents to obtain information about the state of the cell, including its metabolism. It has previously been used mainly to distinguish between healthy and tumor cells, but recent studies have shown that it can also be used to assess sperm quality. Similar work was carried out with insect sperm, and Russian scientists decided to find out how effective the method would be for humans. The researchers sampled the semen of 20 healthy volunteers and analyzed them using FLIM.

Specialists of Sechenov University announced the creation of a new method for selecting the highest quality and viable sperm

This is one of the first studies of human sperm by a similar method. Our task was to find those sperm that have no DNA damage. The method is based on fluorescent response analysis of flavin mononucleotide (FAD) molecules, which are involved in many metabolic processes, including DNA repair, Krebs cycle and oxidative phosphorylation. It is logical to assume that changes in FAD metabolism can be observed in sperm with damaged DNA or impaired energy metabolism. In addition, recent genetic studies have shown a link between FAD metabolism and sperm functional status. Mutations leading to a change in FAD homeostasis are also responsible for male fertility, "said Elena Nikonova, one of the authors of the study, junior researcher at the Laboratory of Clinical Biophotonics at Sechenov University.

The university stressed that the methods existing by July 2023 allow assessing the quality of sperm in general, but they will not help choose the most suitable for artificial insemination of sperm. Embryologists do this manually, taking sperm cells with optimal motility and without morphological disorders under a microscope. FLIM, according to preliminary data, does not affect the viability of sperm, and also allows you to exclude cells with damaged DNA. This makes FLIM a promising method not only to assess the state of sperm in general, but also to select the healthiest and highest quality sperm.^[1]

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