A lateral-flow dipstick (short: LFD) is a detection platform based on the lateral-flow principle. This is capillary forces move a liquid along the surface (= lateral) of a membrane.

Neither use nor read-out of a LFD require a device: the liquid transport is done by capillary forces, and the read-out is possible by the human eye. Expensive detection technique is not required.

Set-up of a Lateral-Flow Dipstick
Fig.: Set-up of a Lateral-Flow Dipstick

A lateral-flow dipstick cosists of several so-called "pads" and a membrane:

  1. The "sample application pad" (SAP): here the liquid to analyse is applied, which may contain the target molecules.
  2. The "conjugate release pad" (CRP): contains dried detection particles conjugated with marker molecules. The liquid to analyse dissolves these particles. The target molecules bind to the marker molecules and thus to the particles.
  3. The lateral-flow membrane: here capture molecules are immobilized in lines. The liquid flow in the membrane transports the particles past these capture molecules. If the target molecules bind here also, then particles accumulate at the line. If enough particles are accumulated, the staining gets visible for the human eye.
  4. The "wicking pad" (Wick): This is the pad where the liquid flows to. It soaks up the liquid.

Usually a lateral-flow dipstick has two lines on the membrane: a test line and an assay control. The assay control checks if the conjugate, i.e. the binding between detection particles and it's marker molecule is still intact.

AMODIA offers several variations of lateral-flow strips, which differ in the number of detectable amplification products (v. here).

It is possible to use optical readers in order to quantify the resulting line intensities. Please get in contact!