scholarly journals Nucleic acid peptide nanogels for the treatment of bacterial keratitis

Nanoscale ◽  
2020 ◽  
Vol 12 (33) ◽  
pp. 17411-17425
Author(s):  
Sybil Obuobi ◽  
Venkatesh Mayandi ◽  
Nurul Azlyn Mohd Nor ◽  
Benedict Jiasheng Lee ◽  
Rajamani Lakshminarayanan ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Bacterial Keratitis ◽  
Fast Resolution

DNA nanogels were developed with rapid in situ loading of L12 peptides during thermal hybridization. This facile strategy retained peptide efficacy to achieve fast resolution of bacterial keratitis.

High-resolution nucleic acid sequence mapping via in situ hybridization at the Electron Microscope level

1995 ◽  
Vol 53 ◽  
pp. 752-753
Author(s):  
B.A. Hamkalo ◽  
S. Narayanswami ◽  
A.P. Kausch
Keyword(s):  
Nucleic Acid ◽  
Interphase Nucleus ◽  
Genome Mapping ◽  
Precise Location ◽  
Electron Microscope Level ◽  
Rna Sequences ◽  
Fundamental Interest ◽  
Whole Cells ◽  
Dna And Rna

The availability of nonradioactive methods to label nucleic acids an the resultant rapid and greater sensitivity of detection has catapulted the technique of in situ hybridization to become the method of choice to locate of specific DNA and RNA sequences on chromosomes and in whole cells in cytological preparations in many areas of biology. It is being applied to problems of fundamental interest to basic cell and molecular biologists such as the organization of the interphase nucleus in the context of putative functional domains; it is making major contributions to genome mapping efforts; and it is being applied to the analysis of clinical specimens. Although fluorescence detection of nucleic acid hybrids is routinely used, certain questions require greater resolution. For example, very closely linked sequences may not be separable using fluorescence; the precise location of sequences with respect to chromosome structures may be below the resolution of light microscopy(LM); and the relative positions of sequences on very small chromosomes may not be feasible.

scholarly journals Locked Nucleic Acid In situ Hybridization Analysis of miR-21 Expression during Colorectal Cancer Development

2009 ◽  
Vol 15 (12) ◽  
pp. 4009-4016 ◽  
Author(s):  
Nobutake Yamamichi ◽  
Ryoichi Shimomura ◽  
Ken-ichi Inada ◽  
Kouhei Sakurai ◽  
Takeshi Haraguchi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
In Situ Hybridization ◽  
Nucleic Acid ◽  
Hybridization Analysis ◽  
Locked Nucleic Acid ◽  
Cancer Development

scholarly journals Improved In Situ Hybridization Efficiency with Locked-Nucleic-Acid-Incorporated DNA Probes

2006 ◽  
Vol 72 (8) ◽  
pp. 5311-5317 ◽  
Author(s):  
Kengo Kubota ◽  
Akiyoshi Ohashi ◽  
Hiroyuki Imachi ◽  
Hideki Harada
Keyword(s):  
In Situ Hybridization ◽  
Nucleic Acid ◽  
Fluorescence Intensity ◽  
Dna Probes ◽  
Locked Nucleic Acid ◽  
Factors Affecting ◽  
Hybridization Efficiency ◽  
Probe Hybridization ◽  
Major Factors

ABSTRACT Low signal intensity due to poor probe hybridization efficiency is one of the major drawbacks of rRNA-targeted in situ hybridization. There are two major factors affecting the hybridization efficiency: probe accessibility and affinity to the targeted rRNA molecules. In this study, we demonstrate remarkable improvement in in situ hybridization efficiency by applying locked-nucleic-acid (LNA)-incorporated oligodeoxynucleotide probes (LNA/DNA probes) without compromising specificity. Fluorescently labeled LNA/DNA probes with two to four LNA substitutions exhibited strong fluorescence intensities equal to or greater than that of probe Eub338, although these probes did not show bright signals when they were synthesized as DNA probes; for example, the fluorescence intensity of probe Eco468 increased by 22-fold after three LNA bases were substituted for DNA bases. Dissociation profiles of the probes revealed that the dissociation temperature was directly related to the number of LNA substitutions and the fluorescence intensity. These results suggest that the introduction of LNA residues in DNA probes will be a useful approach for effectively enhancing probe hybridization efficiency.

scholarly journals Influence of prolonged formalin fixation of tissue samples on the sensitivity of chromogenic in situ hybridization

2011 ◽  
Vol 23 (6) ◽  
pp. 1212-1216 ◽  
Author(s):  
Meike M. Mostegl ◽  
Barbara Richter ◽  
Nora Dinhopl ◽  
Herbert Weissenböck
Keyword(s):  
In Situ Hybridization ◽  
Nucleic Acid ◽  
Signal Intensity ◽  
Formalin Fixation ◽  
Proteinase K ◽  
Cross Linking ◽  
Fixation Time ◽  
Tissue Samples ◽  
Chromogenic In Situ Hybridization

Chromogenic in situ hybridization (ISH) is a commonly used tool in diagnostic pathology to detect pathogens in formalin-fixed, paraffin-embedded (FFPE) tissue sections. Prolonged formalin fixation time was identified to be a limiting factor for the successful detection of nucleic acid from different pathogens, most probably due to the cross-linking activity of formalin between RNA, DNA, and proteins. Therefore, in the current study, the influence of formalin fixation time on ISH signal intensity of 2 viral ( Porcine circovirus-2 [PCV-2] and Porcine respiratory and reproductive virus [PRRSV]) and 2 protozoal agents ( Cryptosporidium serpentis and Tritrichomonas sp.) was evaluated. Tissue samples were fixed in 7% neutral buffered formaldehyde solution, and at defined intervals, pieces were embedded in paraffin wax and subjected to pathogen-specific ISH. For all 4 pathogens, the signal intensity remained comparable with the starting ISH signal for different periods of fixation (PCV-2: 6 weeks, PRRSV: 23 weeks, C. serpentis: 55 weeks, Tritrichomonas sp.: 53 weeks). Thereafter, the signal started to decline until loss of nucleic acid detection. The influence of increased proteinase K concentrations for inverting the formalin-induced cross-linking activity was examined compared with the standard protocol. With all 4 infectious agents, a 4-fold proteinase K concentration restored the ISH signals to a level comparable with 1 day of fixation. In conclusion, the influence of prolonged formalin fixation on the intensity of detected ISH signal highly depends on the analyzed infectious agent and the pretreatment protocol.

Distinguishing L from M photopigment coding sequences by hybridization to novel locked nucleic acid (LNA) oligonucleotide probes

2008 ◽  
Vol 25 (3) ◽  
pp. 283-287
Author(s):  
CHRISTINA PETTAN-BREWER ◽  
LI FU ◽  
SAMIR S. DEEB
Keyword(s):  
Nucleic Acid ◽  
Locked Nucleic Acid ◽  
Macaca Nemestrina ◽  
Oligonucleotide Probes ◽  
Coding Sequences ◽  
Cone Mosaic ◽  
Target Nucleic Acid ◽  
High Degree

Many attempts have been made over the years to distinguish human and primate L (long-wavelength sensitive) from M (middle-wavelength sensitive) cone photoreceptors using either immunohistochemistry or in situ hybridization. These attempts have been unsuccessful due to the very high degree of identity between the sequences of the L and M proteins and encoding mRNAs. The recent development of chemically modified oligonucleotide probes, referred to as locked nucleic acid (LNA) probes, has shown that they hybridize with much greater affinity and specificity to the target nucleic acid. This has greatly increased the potential for differentiating L from M cones by in situ hybridization. We have designed LNA oligonucleotide probes that are complementary to either the L or M coding sequences located in exon 5 of the Macaca nemestrina L and M pigment genes. We have shown that the LNA-M and LNA-L probes hybridize specifically to their respective target nucleic acid sequences in vitro. This result strongly suggests that these probes would be instrumental in rapidly distinguishing L from M cone in the entire retina, and in defining the cone mosaic during development and in adults.

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