Test plate for immunoassay reader

A test plate for determining a performance of a device for detecting spots in a substrate on a bottom of a well of a multi-well plate, wherein the spots indicate analyte-secreting cells of a sample, and wherein the device comprises:

• one or more light sources configured to illuminate the substrate through the well;
• an imaging device comprising a CCD or CMOS sensor configured to detect photons emitted or reflected from the substrate;
• a positioning stage configured to move the multi-well plate into a field of view of the imaging device such that a focal plane of the imaging device coincides with the substrate;
• and
• processing circuitry coupled to the imaging device and configured to detect the spots in the substrate based on the photons, the test plate comprising:
• a plurality of wells;
• a first test structure on a bottom of a first one of the wells, comprising a fluorescent material configured to emit photons in response to illumination by the one or more light sources, thereby allowing the processing circuitry to determine a parameter indicating an intensity of illumination;
• and
• a second test structure on a bottom of a second one of the wells, comprising a pattern of features defining a first area with relatively high photon reflection or fluorescence and a second area with relatively low photon reflection or fluorescence, thereby allowing the processing circuitry to determine a parameter indicating a focus level of the imaging device based on detected photons reflected or emitted by the pattern, as well as on a transition between the first area and the second area.

A method for determining a performance of a system for detecting spots in a substrate arranged on a bottom of a well of a multi-well plate, wherein the spots indicate analyte-secreting cells of a sample, the method comprising:

• illuminating a first test structure on a bottom of a first well of a multi-well test plate, the first test structure comprising a fluorescent material emitting photons when illuminated;
• illuminating a second test structure on a bottom of a second well of the test plate, the second test structure comprising a pattern of features defining a first area with a relatively high photon reflection or fluorescence and a second area with a relatively low photon reflection of fluorescence;
• moving the test-plate using a positioning stage such that the first and second test structures are positioned within a field of view of an imaging device and such that a focal plane of the imaging device coincides with the first and second test structures;
• detecting photons emitted or reflected from the illuminated first and second test structures using the imaging device;
• determining a parameter indicating an intensity of the illumination based on detected photons emitted by the fluorescent material;
• and
• determining a parameter indicating a focus level of the imaging device based on detected photons reflected or emitted by the pattern, as well as on a transition between the first area and the second area.