System for observing a well plate

A system for observing a plate including a set of wells, an optical axis being defined for each well, the observation system including, for each well:

• a light source propagating along a propagation line, the source comprising:
• a light-emitting diode capable of producing a light ray,
• a pinhole, and
• a light integrator capable of guiding the light by reflections between two ends, the first end collecting the radiation from the light-emitting diode and the second end being across from the pinhole, the light integrator having a length defined as the distance between the two ends and an average transverse dimension, the integrator being configured so that the radiation at the output of the integrator does not have an intensity gradient greater than 25 percent,
• an optical sensor able to collect the optical signal from the well, an optical axis being defined for the optical sensor,
• the system being such that the optical axes are parallel to one another and at least one of the following characteristics is verified:
• a ratio between the length and the average transverse dimension of each light integrator is greater than or equal to 2.2, or
• the observation system includes, for each light source, a lens capable of focusing the radiation toward the well, an optical axis being defined for the lens, and at least one optical axis is off-centered relative to the propagation line, the ratio between the length and the average transverse dimension of the integrator being greater than or equal to 1.5.