ABSTRACT
The persistent infection of high-risk-human papillomavirus type 16 (HPV16) is considered an essential element for suffering cervical cancer. Despite polymerase chain reaction, loop-mediated amplification, and microfluidic chips are used to detect the HPV16, these methods still exist some drawbacks including time-consuming and false positive results. The CRISPR-Cas system is widely used in the region of biological detection due to its precise targeted recognition capability. In this contribution, the novel solution-gated graphene transistor sensor is designed to realize the unamplified and label-free detection of HPV16 DNA. Using the precise recognition of the CRISPR-Cas12a system and the gate functionalization, HPV16 DNA can be precisely identified without need the amplification and labeling. The limit of detection of the sensor can be up to 8.3 × 10-18 m and the detection can be within 20 min. Additionally, the heat-Inactivated clinical samples can be clearly distinguished by the sensor the diagnosis results have a high degree of agreement with q-PCR detection.
Subject(s)
CRISPR-Cas Systems , Graphite , Humans , Human papillomavirus 16/genetics , DNA/genetics , Nucleic Acid Amplification TechniquesABSTRACT
SARS-CoV-2 is the etiologic agent of COVID-19, which has led to a dramatic loss of human life and presents an unprecedented challenge to public health worldwide. The gold standard assay for SARS-CoV-2 identification is real-time polymerase chain reaction; however, this assay depends on highly trained personnel and sophisticated equipment and may suffer from false results. Thus, a serological antibody test is a supplement to the diagnosis or screening of SARS-CoV-2. Here, we develop and evaluate the diagnostic performance of an IgM/IgG indirect ELISA method for antibodies against SARS-CoV-2 in COVID-19. The ELISA was constructed by coating with a recombinant nucleocapsid protein of SARS-CoV-2 on an enzyme immunoassay plate, and its sensitivity and specificity for clinical diagnosis of SARS-CoV-2 infection was assessed by detecting the SARS-CoV-2-specific IgM and IgG antibodies in COVID-19 patient's sera or healthy person's sera. The SARS-CoV-2 positive serum samples (n = 168) were collected from confirmed COVID-19 patients. A commercial nucleocapsid protein-based chemiluminescent immunoassay (CLIA) kit and a colloidal gold immunochromatography kit were compared with those of the ELISA assay. The specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of IgM were 100, 95.24, 100, and 91.84%, whereas those of IgG were 100, 97.02, 100, and 94.74%, respectively. We developed a highly sensitive and specific SARS-CoV-2 nucleocapsid protein-based ELISA method for the diagnosis and epidemiologic investigation of COVID-19 by SARS-CoV-2 IgM and IgG antibody detection.
Subject(s)
Coinfection/virology , Coronavirus Infections/complications , Coronavirus Infections/virology , Pneumonia, Viral/complications , Pneumonia, Viral/virology , Adolescent , Betacoronavirus/pathogenicity , COVID-19 , Child , Child, Preschool , Coronavirus Infections/diagnosis , Female , Humans , Male , Metapneumovirus/pathogenicity , Mycoplasma pneumoniae/pathogenicity , Pandemics , Paramyxoviridae Infections/complications , Pneumonia, Mycoplasma/complications , Pneumonia, Viral/diagnosis , Respiratory Syncytial Virus Infections/complications , Respiratory Syncytial Virus, Human/pathogenicity , SARS-CoV-2ABSTRACT
BACKGROUND: ADH1B Arg48His polymorphism is associated with the development of alcohol-related diseases. In this study, we aimed to explore an improved polymerase chain reaction with confronting two-pair primers (PCR-CTPP) assay for the detection of ADH1B Arg48His polymorphism. METHODS: A mismatch was introduced at the 3' end of each of the two allele-specific to increase the specificity of the reaction. But beyond that, a new mismatch at-3 positions of outer primers was designed to decrease the efficiency of the aforementioned primers and depresses the amplification of an internal nonspecific DNA control. A total of 180 samples from healthy volunteers Han Chinese were tested to evaluate this new assay. RESULTS: The protocol of PCR-CTPP was successful for genotyping of ADH1B Arg48His. The results from the improved PCR-CTPP assay were confirmed by Sanger sequencing, and correct genotyping rates were 100%.The genotype frequencies were 49.44% (89 cases) for His/His, 46.67% (84 cases) for Arg/His, and 3.89% (seven cases) for Arg/Arg respectively. CONCLUSIONS: This improved PCR-CTPP assay is simple, rapid, cost-effective, and reliable, specific for the detection of ADH1B Arg48His polymorphism in most clinical diagnostic laboratories.
