HeLa metaphase chromosome spreads were hybridized with centromeric biotinylated DNA probes and detected with gold-conjugated anti-biotin antibodies. Chromosomes were observed by an in-lens field emission scanning electron microscope (FEISEM), which permits detection of biological samples without any coating. DNA probes were well localized in the centromeric region of chromosomes and there was clear discrimination between 10 nm fibers that hybridized to DNA probes and those that did not hybridize. This approach shows that in situ hybridization can be directly visualized at the FEISEM level by evaluating only secondary electron emission, which allows physical localization of the hybridized probe with high resolution so that backscatter detection represents only a control. Because chromosomes maintain the 10-nm fiber organization after in situ hybridization procedures, our data suggest that this fiber represents the lowest order of chromatin arrangement that permits transitory DNA denaturation.
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http://dx.doi.org/10.1177/43.4.7897182 | DOI Listing |
Nat Commun
January 2025
School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules, National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, China.
Chip scale DNA synthesis offers a high-throughput and cost-effective method for large-scale DNA-based information storage. Nevertheless, unbiased information retrieval from low-copy-number sequences remains a barricade that largely arises from the indispensable DNA amplification. Here, we devise a simulation-guided quantitative primer-template hybridization strategy to realize massively parallel homogeneous amplification of chip-scale DNA for DNA information storage (MPHAC-DIS).
View Article and Find Full Text PDFAnal Chem
January 2025
State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, PR China.
The development of intelligent nanotheranostic technology that integrates diagnostic and therapeutic functions holds great promise for personalized nanomedicine. However, most of the nanotheranostic agents exhibit "always-on" properties and do not involve an amplification step, which may largely limit imaging contrast and restrict therapeutic efficacy. Herein, we construct a novel nanotheranostic platform (Hemin/DHPs/PDA@CuS nanocomposite) by assembling DNA hairpin probes (DHPs) and hemin on the surface of PDA@CuS nanosheets that enables amplified fluorescence imaging and activatable chemodynamic therapy (CDT) of tumors.
View Article and Find Full Text PDFAnal Chem
January 2025
School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, P. R. China.
DNAzyme-based cascade networks are effective tools to achieve ultrasensitive detection of low-abundance miRNAs. However, their designs are complicated and costly, and the operation is time-consuming. Herein, a novel simple noncascade DNAzyme network is designed and its amplification effect is comparable to or even better than many cascading ones.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Department of Chemistry and Biochemistry, National Chung Cheng University, 621301, Chia-Yi, Taiwan.
A fluorescent aptasensor was developed based on target-induced hairpin conformation switch coupled with nicking enzyme-assisted signal amplification (NESA) to detect the oligomeric form of ß-amyolid peptide (AβO) in cerebrospinal fluid. The hairpin DNA probe (HP) was specifically designed to recognize AβO. When AβO is present in the sensing system, it induces an HP conformational switch and triggers the NESA reaction.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Changchun Institute of Applied Chemistry Chinese Academy of Sciences: Chang Chun Institute of Applied Chemistry Chinese Academy of Sciences, State Key Lab of Electroanalytical Chemistry, 5625 Renmin Street, 130022, Changchun, CHINA.
Solid-state nanopore is a promising single molecular detection technique, but is largely limited by relatively low resolution to small-size targets and laborious design of signaling probes. Here we establish a universal, CRISPR/Cas-Assisted Nanopore Operational Nexus (CANON), which can accurately transduce different targeting sources/species into different DNA structural probes via a "Signal-ON" mode. Target recognition activates the cleavage activity of a Cas12a/crRNA system and then completely digest the blocker of an initiator.
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