Absorbent Pad for Rapid Diagnostic Kits

Product Details : 

Description:

• Absorbent pads, when used, are placed at the distal end of the test strip (Figure ). The primary function of the absorbent pad is to increase the total volume of sample that enters the test strip. This increased volume can be used to wash unbound detector particles away from the test and control lines, thereby lowering the background and enhancing assay sensitivity. Since the volume of sample that ultimately contributes to signal is controlled by the volume required to solubilize the detector particles, and not by the total volume of sample that enters the device, the addition of the absorbent pad may not have a dramatic impact on overall assay sensitivity. If the strip design does not include an absorbent pad, the volume of sample analyzed in the strip is determined solely by the bed volume of the membrane.
  
• There are two major considerations associated with the use of absorbent pads. First, a suitable material must be identified, specified, purchased, and integrated into the manufacturing process. Ultimately, this leads to a higher cost for the finished product. Second, an absorbent pad makes it difficult to incorporate an end-of-assay indicator in the test device. The flow of liquid through the absorbent pad is not necessarily laminar, and the pad may fill with liquid unpredictably.
  
• Most absorbent pads are made from cellulose filters. The material should be selected on the basis of thickness, compressibility, manufacturability, and, most of all, uniformity of bed volume. Once an absorbent material has been chosen, optimizing the overall volume absorbed by the test strip is best managed by changing the dimensions (usually the length) of the absorbent pad.
  
• Specifying the Absorbent Pad
  
• All of the specifications for the sample pad apply to the absorbent pad, with the exception of extractables.