A novel fluorescent platform of DNA-stabilized silver nanoclusters based on exonuclease III amplification-assisted detection of Salmonella Typhimurium

2021 ◽  
pp. 338903
Author(s):  
Xinyan Yang ◽  
Lihan Wang ◽  
Lidong Pang ◽  
Shiqian Fu ◽  
Xue Qin ◽  
...  
2014 ◽  
Vol 6 (15) ◽  
pp. 6082-6087 ◽  
Author(s):  
Hui Ma ◽  
Wei Wei ◽  
Qian Lu ◽  
Zhixin Zhou ◽  
Henan Li ◽  
...  

A label-free DNA biosensor with high sensitivity and selectivity is constructed by using DNA–Ag NCs and Exo III-catalyzed target recycling amplification.


The Analyst ◽  
2016 ◽  
Vol 141 (10) ◽  
pp. 2998-3003 ◽  
Author(s):  
Wen Yang ◽  
Jianniao Tian ◽  
Lijun Wang ◽  
Shui Fu ◽  
Hongyun Huang ◽  
...  

A label-free and sensitive fluorescence biosensing platform for HIV-DNA detection has been fabricated.


2012 ◽  
Vol 33 (2) ◽  
pp. 293
Author(s):  
Herbert Ary A. A. C. Nóbrega Sisenando

As plantas medicinais têm sido usadas desde a antiguidade no tratamento de diversas enfermidades humanas. As folhas de Bauhinia monandra são amplamente utilizadas no Brasil como fitoterápico no tratamento do Diabetes Mellitus. A partir das folhas de B. monandra, foi purificada uma lectina galactose-específica, denominada de BmoLL, que também apresentou uma importante capacidade hipoglicemiante. Seguindo as normas propostas pela Portaria nº 116, de 8 de agosto de 1996 do Ministério da Saúde do Brasil, o trabalho objetivou avaliar o potencial de mutagenicidade e toxicidade da BmoLL, mediante autilização dos testes com cepas de Escherichia coli da linhagem CC104 (Teste de mutagênese direta), com cepas de Salmonella typhimurium da linhagem TA (Teste de Kado), com plasmídeo pBCKS (Quebra de DNA plasmidial) e com enzima Exonuclease III (Detecção de sítios abásicos). Os resultados demonstraram que a lectina foi incapaz de aumentar a frequência de mutação reversa das cepas de S. typhimurium, com e sem ativador metabólico. No entanto, uma diminuição significativa na frequência de mutação espontânea foi observada nas cepas de E. coli, especialmente na deficiente de reparo (CC104mutMmutY), sugerindo um potencial antioxidante da lectina. A BmoLL é incapaz de gerar danos genotóxicos ecitotóxicos, com base nas concentrações testadas e nos ensaios realizados.


Author(s):  
Mark Hannibal ◽  
Jacob Varkey ◽  
Michael Beer

Workman and Langmore have recently proposed a procedure for isolating particular chromatin fragments. The method requires restriction endonuclease cutting of the chromatin and a probe, their digestion with two exonucleases which leave complimentary single strand termini and low temperature hybridization of these. We here report simple electron microscopic monitoring of the four reactions involved.Our test material was ϕX-174 RF DNA which is cut once by restriction endonuclease Xho I. The conversion of circles to linear molecules was followed in Kleinschmidt spreads. Plate I shows a circular and a linear DNA molecule. The rate of cutting is shown in Figure 1.After completion of the endonuclease cutting, one portion of the DNA was treated with exonuclease III, an enzyme known to digest the 3' terminals of double helical DNA. Aliquots when examined in the electron microscope reveal a decreasing length of double helix and increasing bushes at the ends.


Author(s):  
Ray Wu ◽  
G. Ruben ◽  
B. Siegel ◽  
P. Spielman ◽  
E. Jay

A method for determining long nucleotide sequences of double-stranded DNA is being developed. It involves (a) the synchronous digestion of the DNA from the 3' ends with EL coli exonuclease III (Exo III) followed by (b) resynthesis with labeled nucleotides and DNA polymerase. A crucial factor in the success of this method is the degree to which the enzyme digestion proceeds synchronously under proper conditions of incubation (step a). Dark field EM is used to obtain accurate measurements on the lengths and distribution of the DNA molecules before and after digestion with Exo III, while gel electrophoresis is used in parallel to obtain a mean length for these molecules. It is the measurements on a large enough sample of individual molecules by EM that provides the information on how synchronously the digestion proceeds. For length measurements, the DNA molecules were picked up on 20-30 Å thick carbon-aluminum films, using the aqueous Kleinschmidt technique and stained with 7.5 x 10-5M uranyl acetate in 90% ethanol for 3 minutes.


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