A lateral flow assay device includes a housing, and a test strip disposed within the housing having a membrane with a detection region and a collection region. A sample meter includes a first end for absorption of a test sample, and a storage section that receives and stores at least a component of the test sample. An opening in the housing is sized for insertion of the sample meter into the housing such that the storage section of the sample meter is disposed adjacent the collection region of the membrane. The test sample component is transferable from the storagesection to the collection region for subsequent migration to the detection region. An activatable isolation mechanism is provided within the housing and is disposed so as to isolate portions of the sample meter storage section upon activation thereof such that a defined length of the storage section is presented to the collection region of the membrane.