Method for detecting an analyte of interest in a sample. The method can include providing a container including a microstructured surface, and centrifuging the container toward the microstructured surface to form a sediment and a supernatant of the sample. Following centrifugation, the container can be inverted to decant at least a portion of the supernatant of the sample from the second portion, such that a concentrate (e.g., including the sediment) of the sample is retained in the microstructured surface. The concentrate can then be interrogated in the microstructured surface for the analyte of interest. In some embodiments, at least a portion of the second portion can be substantially transparent, such that the concentrate can be interrogated from the outside of the container, without requiring that the container be opened prior to interrogation.