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Download fileImmunochromatographic Assay on Thread
journal contribution
posted on 2012-09-18, 00:00 authored by Gina Zhou, Xun Mao, David JunckerLateral-flow immunochromatographic assays are low-cost,
simple-to-use,
rapid tests for point-of-care screening of infectious diseases, drugs
of abuse, and pregnancy. However, lateral flow assays are generally
not quantitative, give a yes/no answer, and lack multiplexing. Threads
have recently been proposed as a support for transporting and mixing
liquids in lateral-flow immunochromatographic assays, but their use
for quantitative high-sensitivity immunoassays has yet to be demonstrated.
Here, we introduce the immunochromatographic assay on thread (ICAT)
in a cartridge format that is suitable for multiplexing. The ICAT
is a sandwich assay performed on a cotton thread knotted to a nylon
fiber bundle, both of which are precoated with recognition antibodies
against one target analyte. Upon sample application, the assay results
become visible to the eye within a few minutes and are quantified
using a flatbed scanner. Assay conditions were optimized, the binding
curves for C-reactive protein (CRP) in buffer and diluted serum were
established and a limit of detection of 377 pM was obtained. The possibility
of multiplexing was demonstrated using three knotted threads coated
with antibodies against CRP, osteopontin, and leptin proteins. The
performance of the ICAT was compared with that of the paper-based
and conventional assays. The results suggest that thread is a suitable
support for making low-cost, sensitive, simple-to-use, and multiplexed
diagnostic tests.