VIROLOGICA SINICA, February 2011, 26 (1):30-39
DOI 10.1007/s12250-011-3166-5

© Wuhan Institute of Virology, CAS and Springer-Verlag Berlin Heidelberg 2011
A Simple and Rapid Colloidal Gold-based Immunochromatogarpic Strip
Test for Detection of FMDV Serotype A*
Tao Jiang1,2, Zhong Liang2, Wei-wei Ren3, Juan Chen2, Xiao-ying Zhi3,
Guang-yu Qi3, Xiang-tao Liu2 and Xue-peng Cai 2**
(1.Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, China; 2. Key laboratory of Animal
Virology of Ministry of Agriculture, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary
Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; 3. China Agricultural
Vet.Bio.Science and Technlolgy Co.,LTD, Lanzhou 730046, China)

Abstract: A sandwich format immunochromatographic assay for detecting foot-and-mouth disease virus (FMDV)
serotypes was developed. In this rapid test, affinity purified polyclonal antibodies from Guinea pigs which were
immunized with sucking-mouse adapted FMD virus (A/AV88(L) strain) were conjugated to colloidal gold beads
and used as the capture antibody, and affinity purified polyclonal antibodies from rabbits which were immunized
with cell-culture adapted FMD virus (A/CHA/09 strain) were used as detector antibody. On the nitrocellulose
membrane of the immunochromatographic strip, the capture antibody was laid on a sample pad, the detector
antibody was printed at the test line(T) and goat anti-guinea pigs IgG antibodies were immobilized to the control
line(C). The lower detection limit of the test for a FMDV 146S antigen is 11.7ng/ml as determined in serial tests
after the strip device was assembled and the assay condition optimization. No cross reactions were found with
FMDV serotype C, Swine vesicular disease (SVD), Vesicular stomatiti svirus (VSV) and vesicular exanthema of
swine virus (VES) viral antigens with this rapid test. Clinically, the diagnostic sensitivity of this test for FMDV
serotypes A was 88.7% which is as same as an indirect-sandwich ELISA. The specificity of this strip test was 98.2%
and is comparable to the 98.7% obtained with indirect-sandwich ELISA. This rapid strip test is simple, easy and
fast for clinical testing on field sites; no special instruments and skills are required, and the result can be obtained
within 15 min. To our knowledge, this is the first rapid immunochromatogarpic assay for serotype A of FMDV.

Key words: Foot-and-mouth disease virus (FMDV); Lateral flow immunoassay; Serotype A; Identification;
Colloidal gold particle

Foot-and-mouth (FMD) is an acute, highly
contagious infection and febrile disease of ungulates
induced by the Foot-and-mouth virus (FMDV). The
highly contagious nature of the disease and severe
Received: 2010-08-24, Accepted: 2010-12-08
* Foundation item: Financial supported by the Gansu Provincial
Sci. & Tech. Department (1002NKDA037).
** Corresponding author.
Phone: +86-931-8342535, Fax: +86-931-8340977,
E-mail:caixp@vip.163.com

Virol. Sin. (2011) 26: 30-39

mortality in young stock, the loss of yield and the
significant suffering coupled with the major constraint
to international trade in livestock products are the
ultimate reasons for controlling FMDV [10] FMD is
endemic and at a high prevalence in many countries in
Africa, the Middle East and Asia and is also present in
parts of South America. Animal vaccination strategies
are commonly applied in these regions to control the
disease. Vaccination is carried out after swift assessment
of the serotype involved and advice is given on the
suitability of available vaccines for disease control
and any delay in laboratory testing can hinder the
effectiveness of disease control measures [10]. In China,
outbreaks of serotype A FMDV occurred in early
2009 and a 24-h stamping-out policy, in which farm
livestock showing clinical signs of FMD are
condemned, has been employed during outbreaks. A
fast and sensitive diagnosis that can clearly distinguish
different serotypes of FMDV from other disease that
provoke some or all symptoms similar to FMDV is
critical in the case of a suspected outbreak. The quick
identification of the serotype of FMEV is essential for
an emergency vaccination and for tracking the origin
of an outbreak. Additionally, a fast and sensitive
diagnostic method also has economic benefits for the
detection of FMDV free live-stock and meat and for
international animal trade.
In China, routine diagnosis of FMD is carried out at
the National Foot-and-mouth Disease Reference
Laboratory of China (NFMDRLC) at Lanzhou
Veterinary Research Institute (LVRI). The laboratory
routinely receives tissue samples, mainly epithelial
material, for FMDV diagnosis and serotyping. Reverse-
hemagglutination-inhibition (RHAI) has been success
fully used for many years in detecting and typing
FMDV in epithelial tissue samples. Recently, indirect-
sandwich ELISA[3] and RT-PCR[17,18] have been
widely employed, conferring higher sensitivity and
specificity. However, these diagnostic methods can
only be done in centralized laboratories and have
limited applications for on-site detection of viruses
because they require highly trained laboratory personnel,
stable reagents, expensive equipment and multi-step
sample handling and preparation procedures. Immuno-
chromatographic assays, also known as lateral flow
assays or strip assays, has been available for some
time. Currently, it has been widely applied as one of
the new and emerging lab-on-site technologies to
improve laboratory and on-site detection of viruses in
animals and animal products. This technique is based
on an immunochromatographic procedure that utilizes
antigen-antibody properties in a novel manner and
provides rapid detection of analyte[7,11,19]. It can be
easily performed by unskilled personnel and the result
could be obtained within 15-20 min. The easy appli-
cation of test strip for on-site diagnosis in the case of a
suspected disease outbreak would circumvent problems
associated with the transportation of samples to the
laboratory and would speed up diagnosis in emergency
situations. Several rapid chromatographic strip tests or
lateral flow devices (LFD) for the pen- side diagnosis
of FMD have previously been reported [4,5,15,16]. However,
a specific immunochromatographic strip test for typing
FMDV serotypes A has not yet been developed. In
present report, we describe the selection of a pair of
high-specificity anti-serotype A FMDV polyclonal
antibodies to facilitate pen-side diagnosis of serotype-
specific FMDV antigens and the development and
validation of a rapid and sensitive sandwich immuno-
chromatographic assay for FMDV serotype A detection.
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