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  • br Experiments and Methods br Results and


    Experiments and Methods
    Results and Discussion
    Conclusions Here, the interactions between two newly-synthesized carbazole derivative—cationic δ,δ′‑diazacarbazoles and DNA were characterized by several spectroscopic means, including UV–Vis and fluorescence, AFM and fluorescence imaging. The two cationic δ,δ′‑diazacarbazoles were testified to bind to DNA. DPDPI has a methyl group to replace NH on MPDPI, revealing greater intercalation to DNA than MPDPI, which was proved by the intrinsic binding constant Kb, CD analysis of DNA and analysis of node numbers distributions of plasmid dsDNA. As far as we know, there were no reports about studying the binding properties of MPDPI or similar compounds with dsDNA. The researches on the characterizing the binding properties between the carbazole derived compounds (such as δ,δ′‑diazacarbazole in this study) and DNA would help the understandings and potential applications of δ,δ′‑diazacarbazole related compounds as DNA binders or anti-cancer drugs with DNA as targets. More interestingly, fluorescence enhancement of the cationic δ,δ′‑diazacarbazoles occurred with the addition of DNA, and the intensity of fluorescence emission increased with ionic strength increasing. This phenomenon indicated that the cationic δ,δ′‑diazacarbazoles would be potential DNA-targeted fluorescent probes. Further, cell staining study revealed that DPDPI was membrane-permeable and absorbed by viable cells. Although cationic δ,δ′‑diazacarbazoles might be promising reagents for DNA-targeted fluorescent probe and cell staining, more structural modifications should be applied to shift the additional info to the long wave, and to specify the subcellular localization.
    During an investigation following criminal actions, it has been shown that body fluid traces can be essential as they are very informative for the investigation itself. Moreover can often happen that there is the need for biological fluid to be reinvestigated, in consideration of current techniques in the forensic field to identify the perpetrator several decades after the crime has occurred. Recent studies of seminal fluid traces dated from 20 up to 50 years old, indicate that with current forensic method it has been possible to succeed in the analysis., , , , , The following study was performed to investigate a handkerchief which contained biological traces of what was presumed to be seminal fluid deposited 100 years earlier, using forensic examination methods including: Alternative Light Source (ALS), Prostate-Specific Antigen (PSA) Membrane Test Assays, autosomal and Y-chromosome Short Tandem Repeats (STRs) analysis. Our aim is to verify whether it is possible to exceed the limit of success achieved with semen stain stored up to 50 years old where only a partial profile was obtained. It was essential to preserve the handkerchief, being a historical find, it was possible highlighting parts covering the highest content of biological material in order to investigate the smallest fabric samples without destroying the specimen. Molecular analysis generally involves the destruction of material. It is important to minimize the conflict between this fact and the need to preserve defense guarantees or to protect historical specimen.
    Introduction Being the fundamental unit of life, DNA plays the vital role in long-term storage of information in the form of genetic code to instruct the cellular development and genetic propagation. The temporal profile of structural and morphological architecture of DNA provides a deep insight into molecular pathology, medical diagnosis as well as bioanalytics [1], [2], [3], [4], [5]. Besides, the gross study revealed that DNA revolutionized the social aspects of life also through its influential impact on forensics [6], bioterrorism control [7] as well as agriculture and farming industry [8], [9]. In this sense, because of its vitality for life, the selective detection and molecular imaging of DNA became a dire need and the subject of immense curiosity for biochemical research community. As a result of continuous efforts, fluorescence microscopy has grown as an ideal modality in the field of molecular imaging and cellular recognition [5]. In this context, commercialized dyes such as TOTO, YOYO [10] and cyanine dyes [11], well known for their DNA specificity and quantum efficiency, have been used successfully for the understanding of nuclear dynamics. Moreover, through decades of efforts stains such as thiazole orange [11], oxazole yellow [12], piperazine containing dyes [13] and indole-quinolinium cyanine [14] also came into existence. But the choice of a promising nuclear stain with enhanced discriminative expertise toward DNA as compared to RNA is still a critical issue. In addition, highly specific DNA dye with strong photostability and low phototoxicity is rare. Hence, the frequent inadequacies of the reported nuclear stains necessitated the rational design and adaptation of their molecular framework to meet their appreciable selectivity, biocompatibility, membrane permeability [15], low cytotoxicity [16] and less susceptibility toward photobleaching [17] for their wide applicability as nucleus targeting stains in the fields of molecular imaging, clinical as well as biomedical research.