scholarly journals CRISPR-based surveillance for COVID-19 using genomically-comprehensive machine learning design

Author(s):  
Hayden C. Metsky ◽  
Catherine A. Freije ◽  
Tinna-Solveig F. Kosoko-Thoroddsen ◽  
Pardis C. Sabeti ◽  
Cameron Myhrvold

AbstractThe emergence and outbreak of SARS-CoV-2, the causative agent of COVID-19, has rapidly become a global concern and has highlighted the need for fast, sensitive, and specific tools to surveil circulating viruses. Here we provide assay designs and experimental resources, for use with CRISPR-based nucleic acid detection, that could be valuable for ongoing surveillance. We provide assay designs for detection of 67 viral species and subspecies, including: SARS-CoV-2, phylogenetically-related viruses, and viruses with similar clinical presentation. The designs are outputs of algorithms that we are developing for rapidly designing nucleic acid detection assays that are comprehensive across genomic diversity and predicted to be highly sensitive and specific. Of our design set, we experimentally screened 4 SARS-CoV-2 designs with a CRISPR-Cas13 detection system and then extensively tested the highest-performing SARS-CoV-2 assay. We demonstrate the sensitivity and speed of this assay using synthetic targets with fluorescent and lateral flow detection. Moreover, our provided protocol can be extended for testing the other 66 provided designs. Assay designs are available at https://adapt.sabetilab.org/.

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243319
Author(s):  
Takeshi Hanami ◽  
Tetsuya Tanabe ◽  
Takuya Hanashi ◽  
Mitsushiro Yamaguchi ◽  
Hidetaka Nakata ◽  
...  

Here, we report a rapid and ultra-sensitive detection technique for fluorescent molecules called scanning single molecular counting (SSMC). The method uses a fluorescence-based digital measurement system to count single molecules in a solution. In this technique, noise is reduced by conforming the signal shape to the intensity distribution of the excitation light via a circular scan of the confocal region. This simple technique allows the fluorescent molecules to freely diffuse into the solution through the confocal region and be counted one by one and does not require statistical analysis. Using this technique, 28 to 62 aM fluorescent dye was detected through measurement for 600 s. Furthermore, we achieved a good signal-to-noise ratio (S/N = 2326) under the condition of 100 pM target nucleic acid by only mixing a hybridization-sensitive fluorescent probe, called Eprobe, into the target oligonucleotide solution. Combination of SSMC and Eprobe provides a simple, rapid, amplification-free, and high-sensitive target nucleic acid detection system. This method is promising for future applications to detect particularly difficult to design primers for amplification as miRNAs and other short oligo nucleotide biomarkers by only hybridization with high sensitivity.


2016 ◽  
Vol 16 (7) ◽  
pp. 7069-7076
Author(s):  
Jun Yu ◽  
Zhu Chen ◽  
Chao Wang ◽  
Yana Hu ◽  
Hongming Dong ◽  
...  

2020 ◽  
Vol 20 (3) ◽  
pp. 1401-1408 ◽  
Author(s):  
Chao Wang ◽  
Zhukang Guo ◽  
He Zhu ◽  
Nongyue He ◽  
Zhu Chen ◽  
...  

In the automated high-throughput nucleic acid detection system, we need to grip and transfer consumables frequently when carrying out multichannel nucleic acid detection. In order to ensure the efficiency of experiments and solve problems of the deflection and drop when transferring microplates, we design a self-locking mechanical gripper which consists of a rotary positioning module and a gripping module. The absolute position encoder fixed on the top of the stepper motor can collect the position data of the mechanical gripper in real time and send them to the master control board based on STM32 for processing, which ensures the accuracy of the movement of the mechanical gripper. We used SolidWorks to build models of the mechanical gripper and different microplates, and we carried on finite element analysis of microplates to find the suitable gripping position. Through the force analysis, we obtained the pressure distribution and the deformation of different microplates, and defined the effective gripping areas, which is important to the grip and transfer of microplates.


2021 ◽  
Author(s):  
Zihan Li ◽  
Wenchang Zhao ◽  
Shixin Ma ◽  
Zexu Li ◽  
Yingjia Yao ◽  
...  

The CRISPR-based nucleic acid detection systems such as SHERLOCK, DETECTR and HOLMES have shown great potential for point-of-care testing of viral pathogens, especially in the context of COVID-19 pandemic. Here we optimize several key parameters of reaction chemistry and develop a Chemical Enhanced CRISPR Detection system for nucleic acid (termed CECRID). For the Cas12a/Cas13a-based signal detection phase, we determine buffer conditions and substrate range for optimal detection performance. By comparing several chemical additives, we find that addition of L-proline can secure or enhance Cas12a/Cas13a detection capability. For isothermal amplification phase with typical LAMP and RPA methods, inclusion of L-proline can also enhance specific target amplification as determined by CRISPR detection. Using SARS-CoV-2 pseudovirus, we demonstrate CECRID has enhanced detection sensitivity over chemical additive-null method with either fluorescence or lateral flow strip readout. Thus, CECRID provides an improved detection power and system robustness towards practical application of CRISPR-based diagnostics.


Small ◽  
2014 ◽  
Vol 10 (10) ◽  
pp. 2067-2076 ◽  
Author(s):  
Yuqiang Wu ◽  
David Yu Zhang ◽  
Peng Yin ◽  
Frank Vollmer

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang You ◽  
Pingping Zhang ◽  
Gengshan Wu ◽  
Yafang Tan ◽  
Yong Zhao ◽  
...  

The recent discovery of collateral cleavage activity of class-II clustered regularly interspaced short palindromic repeats–CRISPR-associated protein (CRISPR-Cas) makes CRISPR-based diagnosis a potential high-accuracy nucleic acid detection method. Colloidal gold-based lateral flow immunochromatographic assay (LFA), which has been combined with CRISPR/Cas-based nucleic detection, usually associates with drawbacks of relative high background and the subjectivity in naked-eye read-out of the results. Here, we developed a novel system composed of Cas12a-based nucleic acid detection and up-converting phosphor technology (UPT)-based LFA (UPT–LFA), termed Cas12a-UPTLFA. We further demonstrated the utility of this platform in highly sensitive and specific detection of Yersinia pestis, the causative agent of the deadly plague. Due to high infectivity and mortality, as well as the potential to be misused as bioterrorism agent, a culture-free, ultrasensitive, specific, and rapid detection method for Y. pestis has long been desired. By incorporating isothermal recombinase polymerase amplification, the Cas12a-UPTLFA we established can successfully detect genomic DNA of Y. pestis as low as 3 attomolar (aM) and exhibited high sensitivity (93.75%) and specificity (90.63%) for detection of spiked blood samples with a detection limit of 102 colony-forming unit per 100 μl of mouse blood. With a portable biosensor, Cas12a-UPTLFA assay can be operated easily by non-professional personnel. Taken together, we have developed a novel Cas12a-UPTLFA platform for rapid detection of Y. pestis with high sensitivity and specificity, which is portable, not expensive, and easy to operate as a point-of-care method. This detection system can easily be extended to detect other pathogens and holds great promise for on-site detection of emerging infectious pathogens.


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