Method for analyzing a biological sample comprising determination of the spatial distribution of biomass along the optical axis

A method for analyzing a biological sample by means of an analysis instrument, the biological sample comprising biological agents and being disposed in an analysis receptacle in a field of view of a holographic imaging system, the holographic imaging system defining an optical axis and an acquisition focal plane, the method comprising, for each measurement time from a plurality of measurement times of a measurement period:

• the acquisition of a plurality of holographic images of the biological sample at various respective positions on the optical axis of the acquisition focal plane,
• the determination, from each acquired holographic image, of a value of a biomass parameter representative of the quantity of biological agents at the position of the acquisition focal plane of said holographic image,
• the method comprising the construction of a distribution indicator using values of the biomass parameter from the same measurement time for several positions of the acquisition focal plane, the distribution indicator being representative of the spatial distribution of the quantity of biological agents in the analysis receptacle along the optical axis at a measurement time, and the provision, from amongst the analysis results, of a representation of the distribution of the biomass of biological agents derived from at least one distribution indicator at one measurement time.