Cartridges for immunoassay tests and methods of using the same

A method for conducting an immunoassay test, the method comprising:

• obtaining a cartridge that includes—
• a sample well that contains a sample,
• a reagent well that contains a reagent,
• a first wash well that contains a first aqueous solution,
• a second wash well that contains a second aqueous solution, and
• a measurement well in which light is shone for optical reading during the immunoassay test;
• and
• loading a probe into the sample well, the first wash well, the reagent well, the second wash well, and the measurement well in succession,
• wherein said loading is performed such that a bottom tip of the probe that is coated with analyte-binding molecules is immersed in the sample, the first aqueous solution, the reagent, and the second aqueous solution before being exposed to the light.