Devices and methods for examining drug effects on microorganisms

A method for examining an effect of a test reagent on one or more microorganism individuals in a sample, the method comprising:

• (a) putting the test reagent, the sample, and a detection agent between two plates, wherein the detection agent is a fluorescence stain dye that labels a microorganism individual, and wherein one or both plates have spacers;
• (b) compressing the plates to form a uniform testing layer;
• (c) using an imager to acquire, at at least two discrete time points, images of signals emanating from the microorganism individual in the uniform testing layer;
• and
• (d) analyzing the images at the at least two discrete time points to determine a change of the microorganism individual between the at least two discrete time points;
• wherein the two plates are movable relative to each other into different configurations, including an open configuration and a closed configuration;
• wherein in the open configuration, the two plates are partially or entirely separated apart, the spacing between the plates is not regulated by the spacers, and the sample is deposited on one or both of the plates;
• wherein in the closed configuration, which is configured after deposition of the sample in the open configuration:
• at least part of the sample is compressed by the two plates into the uniform testing layer having a highly uniform thickness, and the uniform thickness of the layer is confined by the sample contact surfaces of the plates and is regulated by the plates and the spacers;
• wherein the imaging is in the closed configuration, and wherein the thickness of the testing layer at the closed configuration is configured such that there is substantially no overlap between any two microorganism individuals;
• and
• wherein in the closed configuration, the thickness of the uniform testing layer is regulated by the two plates and the spacers within the sample area, and the height of the spacers is 250 microns or less.