Cell analysis in body fluids, particularly blood

A device for analyzing an analyte in a sample, comprising:

• a first plate, a second plate, spacers, a reagent, and a landing mark, wherein:
• i. the plates are movable relative to each other into different configurations;
• ii. each of the plates comprises an inner surface that has a sample contact area for contacting a blood sample;
• iii. one or both of the plates comprise the spacers that are permanently fixed on the sample contact area of a respective plate;
• iv. the reagent is coated on one or both of the sample contact areas;
• v. the landing mark is on one of the plates and indicates the location on the plate for depositing the sample;
• and
• vi. the spacers are on one or both of the plates:
• wherein one of the configurations is an open configuration, in which:
• the two plates are partially or completely 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;
• and
• wherein another of the configurations is a closed configuration which is configured after the sample is deposited in the open configuration;
• and in the closed configuration:
• at least part of the sample is compressed by the two plates into a layer of highly uniform thickness and is substantially stagnant relative to the plates, wherein the uniform thickness of the layer is confined by the sample contact areas of the two plates and is regulated by the plates and the spacers.