Sample collection and handling for delayed analysis

A method for sample collection and remote analysis, comprising:

• (a) providing a sample holder comprising a first plate, a second plate, and spacers, wherein:
• (i) the first and second plates are movable relative to each other into different configurations, including an open configuration and a closed configuration;
• (ii) each of the plates comprises a surface that includes a sample contact area for contacting a sample that contains or is suspected of containing an analyte;
• (iii) the spacers are fixed to one of the sample contact areas, wherein the spacers have a predetermined inter-spacer distance and a predetermined height, wherein at least one of the spacers are inside the sample contact area;
• (iv) at least one of the two plates is transparent;
• and
• (v) one or both of the two plates comprise a reagent on a surface thereof,
• (b) collecting the sample to the sample contact area of one or both of the two plates at the open configuration;
• (c) compressing the two plates into the closed configuration;
• (d) imaging, after step (c), at least one image of the sample in the sample holder, wherein the imaging is through the transparent plate;
• (e) sending the sample holder and the at least one image to a remote location;
• and
• (f) analyzing, at the remote location, the sample and the at least one image to measure the analyte, wherein the analyzing uses the predetermined inter-spacer distance and the predetermined height to quantify the volume of the sample at the closed configuration, and uses the at least one image;
• wherein the open configuration is a configuration in which the two plates are partially or entirely separated apart and a spacing between the two plates is not regulated by the spacers,
• wherein in the closed configuration, which is formed after the sample is deposited when the two plates are in the open configuration, at least part of the sample is compressed by the two plates into a layer of highly uniform thickness of 200 μm or less, the layer is confined by the plates, and the thickness of the layer is regulated by the plates and the spacers.