A method for analysing a sample comprising from 0.1 pg to 1 μg of analyte, the method comprising: (a) providing a sample, the sample containing or not containing from 0.1 pg to 1 μg of an analyte of interest; (b) dissolving at least a portion of the sample in a buffer to form a dissolved sample solution; (c) contacting at least a portion of the dissolved sample solution with a probe zone comprising a labelled probe to dissolve at least a portion of the labelled probe and allow the labelled probe to bind with the analyte, where present, in the portion of the dissolved sample solution to form a labelled probe-analyte complex; (d) passing the labelled probe and/or labelled probe-analyte complex through a test site comprising a first immobilised capture reagent capable of binding to the labelled probe; (e) determining whether or not the amount of analyte, if any, in the sample exceeds a threshold value by detecting the amount of labelled probe in the test site; wherein the sample comprises finger-sweat and/or palm-sweat and/or toe-sweat; and wherein the sample is dissolved in step (b) such that the sample is contacted with the probe zone at the solvent front in step (c); wherein the sample provided in step (a) is substantially dry, such that the sample comprises insufficient liquid to move from the sample receiving zone to the probe zone; wherein the method is carried out using a lateral flow device for analysing a sample comprising from 0.1 pg to 1 μg of analyte, the device comprising: a sample receiving portion; a probe zone downstream of the sample receiving portion, the probe zone comprising a labelled probe capable of binding to the analyte; and a test site, downstream of the probe zone, the test site comprising a first immobilised capture reagent capable of binding to the labelled probe; the device being configured to permit movement of a buffer from the sample receiving portion to the probe zone and from the probe zone to the test site. (a) providing a sample, the sample containing or not containing from 0.1 pg to 1 μg of an analyte of interest; (b) dissolving at least a portion of the sample in a buffer to form a dissolved sample solution; (c) contacting at least a portion of the dissolved sample solution with a probe zone comprising a labelled probe to dissolve at least a portion of the labelled probe and allow the labelled probe to bind with the analyte, where present, in the portion of the dissolved sample solution to form a labelled probe-analyte complex; (d) passing the labelled probe and/or labelled probe-analyte complex through a test site comprising a first immobilised capture reagent capable of binding to the labelled probe; (e) determining whether or not the amount of analyte, if any, in the sample exceeds a threshold value by detecting the amount of labelled probe in the test site; a sample receiving portion; a probe zone downstream of the sample receiving portion, the probe zone comprising a labelled probe capable of binding to the analyte; and a test site, downstream of the probe zone, the test site comprising a first immobilised capture reagent capable of binding to the labelled probe; the device being configured to permit movement of a buffer from the sample receiving portion to the probe zone and from the probe zone to the test site.