Functionalisation of Detonation Nanodiamond for Monodispersed, Soluble DNA-Nanodiamond Conjugates Using Mixed Silane Bead-Assisted Sonication Disintegration.
Nanodiamonds have many attractive properties that make them suitable for a range of biological applications, but their practical use has been limited because nanodiamond conjugates tend to aggregate in solution during or after functionalisation.
Here we demonstrate the production of DNA-detonation nanodiamond (DNA-DND) conjugates with high dispersion and solubility using an ultrasonic, mixed-silanization chemistry protocol based on the in situ Bead-Assisted Sonication Disintegration (BASD) silanization method.
We use two silanes to achieve these properties: (1) 3-(trihydroxysilyl)propyl methylphosphonate (THPMP); a negatively charged silane that imparts high zeta potential and solubility in solution; and (2) (3-aminopropyl)triethoxysilane (APTES); a commonly used functional silane that contributes an amino group for subsequent bioconjugation.
We target these amino groups for covalent conjugation to thiolated, single-stranded DNA oligomers using the heterobifunctional crosslinker sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (Sulfo-SMCC).
The resulting DNA-DND conjugates are the smallest reported to date, as determined by Dynamic Light Scattering (DLS) and Atomic Force Microscopy (AFM). The functionalisation method we describe is versatile and can be used to produce a wide variety of soluble DND-biomolecule conjugates.
Validating sonication as a DNA extraction method for use with carrion flies.
Entomological evidence can be critical in establishing a postmortem interval estimate. DNA-based species identification can be an extremely valuable tool for forensic entomology.
The problem of processing samples in a consistent, cost-effective manner that retains the morphological attributes of the specimen for vouchering has led us to investigate sonication as a primary means of non-destructive DNA extraction from carrion flies.
We analyze the efficacy of this technique and compare it to an established DNA extraction technique – the Qiagen DNeasy tissue kit. Our results indicate that sonication produces a significant reduction in the sequence length and lower PHRED quality scores when compared to sequences using DNA obtained using the DNeasy kit, but species identification and phylogenetic inferences between sonication and DNeasy extractions are equivalent.
Physisorption of DNA molecules on chemically modified single-walled carbon nanotubes with and without sonication.
We investigated the physisorption phenomenon of single-stranded DNA (ssDNA) molecules onto two types of commercially available chemically functionalized single-walled carbon nanotubes (SWNTs) by atomic force microscopy (AFM) and agarose gel electrophoresis.
We found that DNA molecules can adsorb on the water-soluble SWNT surfaces without sonication, although sonication treatment has been used for hybridization of DNA and SWNTs in many previous studies.
Using our method, damage of DNA molecules by sonication can be avoided. On the other hand, the amount of DNA molecules adsorbed on SWNT surfaces increased when the samples were sonicated.
This fact suggests that the sonication is effective not only at debundling of SWNTs, but also at assisting DNA adsorption. Furthermore, DNA adsorption was affected by the types of functionalized SWNTs.
In the case of SWNTs functionalized with polyethylene glycol (PEG-SWNT), physisorption of ssDNA molecules was confirmed only by agarose-gel electrophoresis. In contrast, amino-terminated SWNTs (NH2-SWNTs) showed a change in the height distribution profile based on AFM observations.
These results suggest that DNA molecules tended to adsorb to NH2-SWNT surfaces, although DNA molecules can also adsorb on PEG-SWNT surfaces. Our results revealed fundamental information for developing nanobiodevices using hybrids of DNA and SWNTs.
G-quadruplex DNA-based asymmetric catalysis of michael addition: Effects of sonication, ligands, and co-solvents.
There is an escalating interest of using double stranded DNA molecules as a chiral scaffold to construct metal-biomacromolecule hybrid catalysts for asymmetric synthesis. Several recent studies also evaluated the use of G-quadruplex DNA-based catalysts for asymmetric Diels-Alder and Friedel-Crafts reactions.
However, there is still a lack of understanding of how different oligonucleotides, salts (such as NaCl and KCl), metal ligands and co-solvents affect the catalytic performance of quadruplex DNA-based hybrid catalysts. In this study, we aim to systematically evaluate these key factors in asymmetric Michael addition reactions, and to examine the conformational and molecular changes of DNA by circular dichroism (CD) spectroscopy and gel electrophoresis.
We achieved up to 95% yield and 50% enantiomeric excess (ee) when the reaction of 2-acylimidazole 1a and dimethylmalonate was catalyzed by 5′-G3 (TTAG3 )3 -3′ (G4DNA1) in 20 mM MOPS (pH 6.5) containing 50 mM KCl and 40 µM [Cu(dmbipy)(NO3 )2 ], and G4DNA1 was pre-sonicated in ice bath for 10 min prior to the reaction. G-quadruplex-based hybrid catalysts provide a new tool for asymmetric catalysis, but future mechanistic studies should be sought to further improve the catalytic efficiency.
Description: DNAM 1, also known as CD226, is a receptor expressed by peripheral blood T lymphocytes that is involved in intercellular adhesion, lymphocyte signaling, cytotoxicity and lymphokine secretion mediated by cytotoxic T lymphocytes. DNAM 1 is broadly expressed on T cells, NK cells, platelets, monocytes and a subset of B cells. DNAM-1 is also expressed by a subset of CD3 positive thymocytes. This antibody is reported to inhibit T- and NK cell mediated cytotoxicity against tumour cell targets and to block TNF alpha and IFN gamma secretion by alloantigen-specific T-cells.
Description: DNAM 1, also known as CD226, is a receptor expressed by peripheral blood T lymphocytes that is involved in intercellular adhesion, lymphocyte signaling, cytotoxicity and lymphokine secretion mediated by cytotoxic T lymphocytes. DNAM 1 is broadly expressed on T cells, NK cells, platelets, monocytes and a subset of B cells. DNAM-1 is also expressed by a subset of CD3 positive thymocytes. This antibody is reported to inhibit T- and NK cell mediated cytotoxicity against tumour cell targets and to block TNF alpha and IFN gamma secretion by alloantigen-specific T-cells.
Description: A polyclonal antibody for detection of DNAM-1 from Human, Mouse, Monkey. This DNAM-1 antibody is for WB, IHC-P, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from human DNAM-1 around the non-phosphorylation site of S329
Description: A polyclonal antibody for detection of DNAM-1 from Human, Mouse, Monkey. This DNAM-1 antibody is for WB, IHC-P, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from human DNAM-1 around the non-phosphorylation site of S329
Description: A polyclonal antibody for detection of DNAM-1 from Human, Mouse, Monkey. This DNAM-1 antibody is for WB, IHC-P, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from human DNAM-1 around the non-phosphorylation site of S329
Description: A polyclonal antibody for detection of DNAM-1 from Human. This DNAM-1 antibody is for WB, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from the Internal region of human DNAM-1
