scholarly journals Universal and naked-eye gene detection platform based on CRISPR/Cas12a/13a system

2019 ◽  
Author(s):  
Chao-Qun Yuan ◽  
Tian Tian ◽  
Jian Sun ◽  
Meng-Lu Hu ◽  
Xu-Sheng Wang ◽  
...  

AbstractColorimetric gene detection based on gold nanoparticles (AuNPs) is an attractive detection format due to its simplicity. Here, we report a new design for a colorimetric gene-sensing platform based on the CRISPR/Cas system that has improved specificity, sensitivity, and universality. CRISPR/Cas12a and CRISPR/Cas13a have two distinct catalytic activities and are used for specific target gene recognition. Programmable recognition of DNA by Cas12a/crRNA and RNA by Cas13a/crRNA with a complementary sequence activates the nonspecific trans-ssDNA or -RNA cleavage, respectively, thus degrading the ssDNA or RNA linkers which are designed as a hybridization template for the AuNP-DNA probe pair. Target-induced trans -ssDNA or RNA cleavage leads to a distance-dependent color change for the AuNP-DNA probe pair. In this platform, naked eye detection of transgenic rice, African swine fever virus (ASFV), and a miRNA can be completed within 1 hour. Our colorimetric gene-sensing method shows superior characteristics, such as probe universality, isothermal reaction conditions, on-site detection capability, and sensitivity that is comparable to that of the fluorescent detection; thus, this method represents a robust next generation gene detection platform.

2015 ◽  
Vol 19 (06) ◽  
pp. 769-774 ◽  
Author(s):  
Yuanyuan Lv ◽  
Lili Wu ◽  
Wangxing Shen ◽  
Junbo Wang ◽  
Guida Xuan ◽  
...  

A new chemosensor (ProE) based on a functionalized porphyrin for colorimetric and fluorometric detection of cadmium ions ( Cd 2+) was outlined. ProE displays a distinct color change, as well as dramatic ratiometric variations in absorption and fluorescent emission spectra upon exposure to Cd 2+. This condition allows the detection of the analyte at concentrations as low as 0.073 μM. The dual chromo- and fluorogenic responses of the probe are attributed to the formation of a 1:1 Cd 2+/ProE complex, which ultimately affects its optical properties. The sensor also exhibited high selectivity and sensitivity toward Cd 2+ over other common metal ions in a moderate pH range, leading to potential fabrication of both "naked-eye" and ratiometric fluorescent detection of Cd 2+.


2020 ◽  
Vol 23 (04) ◽  
pp. 21-26
Author(s):  
A.K. Sibgatullova ◽  
◽  
M.E. Vlasov ◽  
I.A. Titov ◽  
◽  
...  

1990 ◽  
Vol 64 (5) ◽  
pp. 2064-2072 ◽  
Author(s):  
J M Almendral ◽  
F Almazán ◽  
R Blasco ◽  
E Viñuela

2021 ◽  
pp. 105081
Author(s):  
Zhao Huang ◽  
Lang Gong ◽  
Zezhong Zheng ◽  
Qi Gao ◽  
Xiongnan Chen ◽  
...  

Author(s):  
Tao Wang ◽  
Liang Wang ◽  
Yu Han ◽  
Li Pan ◽  
Jing Yang ◽  
...  

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 757
Author(s):  
Sandra Barroso-Arévalo ◽  
Jose A. Barasona ◽  
Estefanía Cadenas-Fernández ◽  
José M. Sánchez-Vizcaíno

African swine fever virus (ASFv) is one of the most challenging pathogens to affect both domestic and wild pigs. The disease has now spread to Europe and Asia, causing great damage to the pig industry. Although no commercial vaccine with which to control the disease is, as yet, available, some potential vaccine candidates have shown good results in terms of protection. However, little is known about the host immune mechanisms underlying that protection, especially in wild boar, which is the main reservoir of the disease in Europe. Here, we study the role played by two cytokines (IL-10 and IFN-γ) in wild boar orally inoculated with the attenuated vaccine candidate Lv17/WB/Rie1 and challenged with a virulent ASFv genotype II isolate. A group of naïve wild boar challenged with the latter isolate was also established as a control group. Our results showed that both cytokines play a key role in protecting the host against the challenge virus. While high levels of IL-10 in serum may trigger an immune system malfunctioning in challenged animals, the provision of stable levels of this cytokine over time may help to control the disease. This, together with high and timely induction of IFN-γ by the vaccine candidate, could help protect animals from fatal outcomes. Further studies should be conducted in order to support these preliminary results and confirm the role of these two cytokines as potential markers of the evolution of ASFV infection.


Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 29
Author(s):  
Laia Bosch-Camós ◽  
Elisabet López ◽  
María Jesús Navas ◽  
Sonia Pina-Pedrero ◽  
Francesc Accensi ◽  
...  

The development of subunit vaccines against African swine fever (ASF) is mainly hindered by the lack of knowledge regarding the specific ASF virus (ASFV) antigens involved in protection. As a good example, the identity of ASFV-specific CD8+ T-cell determinants remains largely unknown, despite their protective role being established a long time ago. Aiming to identify them, we implemented the IFNγ ELISpot as readout assay, using as effector cells peripheral blood mononuclear cells (PBMCs) from pigs surviving experimental challenge with Georgia2007/1. As stimuli for the ELISpot, ASFV-specific peptides or full-length proteins identified by three complementary strategies were used. In silico prediction of specific CD8+ T-cell epitopes allowed identifying a 19-mer peptide from MGF100-1L, as frequently recognized by surviving pigs. Complementarily, the repertoire of SLA I-bound peptides identified in ASFV-infected porcine alveolar macrophages (PAMs), allowed the characterization of five additional SLA I-restricted ASFV-specific epitopes. Finally, in vitro stimulation studies using fibroblasts transfected with plasmids encoding full-length ASFV proteins, led to the identification of MGF505-7R, A238L and MGF100-1L as promiscuously recognized antigens. Interestingly, each one of these proteins contain individual peptides recognized by surviving pigs. Identification of the same ASFV determinants by means of such different approaches reinforce the results presented here.


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