title: Antigen detection based on background fluorescence quenching immunochromatographic assay.
abstract: Gold immunochromatographic assay (GICA) has been around for quite a while, but it is qualitative in the vast majority of applications. A fast, simple and quantitative GICA is in call for better medicine. In the current study, we have established a novel, quantitative GICA based on fluorescence quenching and nitrocellulose membrane background signals, called background fluorescence quenching immunochromatographic assay (bFQICA). Using model analyte alpha-fetoprotein (AFP), the present study assessed the performance of bFQICA in numerous assay aspects. With serial dilutions of the international AFP standard, standard curves for the calculation of AFP concentration were successfully established. At 10 and 100ngmL(-1) of the international AFP standard, the assay variability was defined with a coefficient of variance at 10.4% and 15.2%, respectively. For samples with extended range of AFP levels, bFQICA was able to detect AFP at as low as 1ngmL(-1). Fluorescence in bFQICA strips stayed constant over months. A good correlation between the results from bFQICA and from a well-established Roche electrochemiluminescence immunoassay was observed in 27 serum samples (r=0.98, p<0.001). In conclusion, our study has demonstrated distinctive features of bFQICA over conventional GICA, including utilization of a unique fluorescence ratio between nitrocellulose membrane background and specific signals (F1/F2) to ensure accurate measurements, combined qualitative and quantitative capabilities, and exceptionally high sensitivity for detection of very low levels of antigens. All of these features could make bFQICA attractive as a model for antigen-antibody complex based GICA, and could promote bFQICA to a broad range of applications for investigation of a variety of diseases.
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, PR China.
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Chen
authors.affiliation: Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Genome Technology Access Center at Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, USA.
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Yu
authors.affiliation: Shanghai Simp Bio-Science Co., Ltd., Shanghai, PR China.
authors.forename: Jiutong
authors.initials: J
authors.lastname: Li
authors.affiliation: Shanghai Simp Bio-Science Co., Ltd., Shanghai, PR China.
authors.forename: Xuelei
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Chuanyong
authors.initials: C
authors.lastname: Wu
authors.affiliation: Shanghai Pulmonary Hospital, Shanghai, PR China.
authors.forename: Qiuliang
authors.initials: Q
authors.lastname: Ji
authors.affiliation: Department of Clinical Laboratory Diagnosis, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Shanghai High & New Technology's Industrialization Promotion Center, Shanghai, PR China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Wang
authors.affiliation: INESA Analytical Instrument Co., Ltd., Shanghai, PR China.
authors.forename: Zhengyi
authors.initials: Z
authors.lastname: Huang
authors.affiliation: INESA Analytical Instrument Co., Ltd., Shanghai, PR China.
authors.forename: Hanling
authors.initials: H
authors.lastname: Zhuang
authors.affiliation: INESA Analytical Instrument Co., Ltd., Shanghai, PR China.
authors.forename: Long
authors.initials: L
authors.lastname: Piao
authors.affiliation: Genome Technology Access Center at Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Head
authors.affiliation: Department of Clinical Laboratory Diagnosis, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China; Core Laboratory for Clinical Medical Research, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China. Electronic address: tiantanwyj@gmail.com.
authors.forename: Yajie
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China. Electronic address: loujiatao@126.com.
authors.forename: Jiatao
authors.initials: J
authors.lastname: Lou
mesh_terms: D000941:Antigens / Q000032:analysis* / Q000737:chemistry; D001681:Biological Assay / Q000379:methods*; D002846:Chromatography, Affinity; D005453:Fluorescence; D013997:Time Factors
chemical_list: D000941:Antigens
keywords: Background fluorescence quenching; Immunochromatography; Nitrocellulose membrane; Point of care test; Quantitative detection