Evolution in Lateral Flow–Based Immunoassay Systems

Abstract

The development of the rapid, immunochromatographic test strip, also known as lateral flow immunoassay (LFIA), is the result of convergence of several threads that can be traced back to the 1950s. However, the concept of rapid diagnostic tests based on body fluids dated back significantly further. Documented evidence of saliva-and urine-based diagnostics existed several thousand years ago. The ancient Chinese were among the first documented users of saliva-based diagnostics. One widely used practice involved the use of saliva as a rapid determinant of guilt. In the ''Rice Test'', the inability to generate enough saliva to swallow a handful of rice was considered sufficient evidence for conviction. In this way, a rapid result was generated, but often with a poor prognosis for the subject. One of the earliest written records of a urine-based diagnostic test for pregnancy can be found in ancient Egyptian documents. There, a test was described whereby a potentially pregnant woman could urinate on wheat and barley seeds over the course of several days. The results: ''If Barley grows, it means a male child. If wheat grows, it means a female child. If both do not grow, she will not bear at all'' [1]. The interest in urine as a rapid diagnostic medium for a variety of ailments continued through the Middle Ages, with the advent of the so-called pissprophets in Europe, who claimed to be able to differentiate many different conditions from the color of urine. Along with many medical concepts of the time, success typically varied. Despite best efforts through the ages, it was not until the mid-twentieth century that the majority of rapid diagnostic methods gained real predictive value.The technical basis of the lateral flow immunoassay was derived from the latex agglutination assay, the first of which was developed in 1956 by Plotz and Singer [2]. In the same period, plate-based immunoassays were being developed.

Lateral Flow Test Using Echinococcus granulosus Native Antigen B and Comparison of IgG and IgG4 Dipsticks for Detection of Human Cystic Echinococcosis

“…After the lined reagents had dried, the membrane card was gently wetted with ELISA blocking solution (Roche) and dried overnight at 37 C. An absorbent pad was added to the top of the membrane card, and the card was cut into 5-mm strips using an automated cutter (Index Cutter-I; A-Point Technologies, Gibbstown, NJ). 26 The strips were stored in a dry cabinet ( 20% humidity) at room temperature until required.…”

Surface enhanced Raman spectroscopy (SERS) for in vitro diagnostic testing at the point of care

“…One of the earliest and most widespread POC devices is based on the concept of lateral flow and used to create off the shelf testing platforms, such as the at-home pregnancy test and glucose self-testing strips [204,205]. In recent years, this same approach has become attractive once again to create rapid detection kits for more complex biological analytes in the early stages of disease ( Figure 12) [206].…”

Immobilizing affinity proteins to nitrocellulose: a toolbox for paper-based assay developers

“…This approach has worked well for a decadelong history of lateral flow tests, dot blots, and even more recent paper-based diagnostic technologies [1][2][3]. The success of direct adsorption in these assays has largely been due to the suitability of immunoglobulin G (IgG) antibodies to this process, which have been the mainstay of capture agents for lateral flow immunoassays [3][4][5]. However, as new paper-based assays are designed with non-antibody affinity reagents, the tried-and-true method of direct adsorption may no longer serve as the most effective method for immobilization.…”