May offer an alternative conjugation reaction with aldehydes and ketones since they form stable oximes. The use of nucleophilic aminooxy modifiers for DNA conjugations was first described in the mid 1990’s.1,2 A number of improvements in oxime conjugation chemistry has led to a more reliable and direct approach for the use of aminooxy modifiers in conjugations with DNA.3,4 The oxime formed from the reaction of alkyloxyamines with aldehydes creates a stable covalent bond. In comparison, the imine formed by the conjugation of primary amines with aldehydes is not stable to acidic or basic conditions and requires subsequent reduction with borohydrides to form stable amine conjugates, as shown in Scheme 1. Glen Research is pleased to offer 5′-AminoOxy-Modifier 11 (1), based on a tetraethylene glycol linkage for improved solubility and for reducing the potential negative impact on hybridization of the oligo. For synthesis, we recommend using 1H-Tetrazole with a 3 minute coupling time. The cleanest approach we have found for solution phase conjugation is to synthesize the oligo DMT-ON and complete the deprotection with ammonium hydroxide or AMA. After drying, the conjugation can be completed in 80% acetic acid to simultaneously remove the DMT group and catalyze the oxime formation.1353016-71-3 custom synthesis Subsequent gel-filtration using a Glen Gel-Pak removes the acetic acid and unreacted aldehydes. This progression of oxime formation with cinnamaldehyde is illustrated in Figure 2. The aminooxy conjugation can also be performed on the column after removal of the 5′-DMT group, provided the label is stable to the subsequent deprotection conditions.4 4
FIGURE 1: struCture oF 5′-AMinooxy-ModiFier
DMT H N O O O O O P O N(iPr)2 CNEt
NEw PRODUcts – BLackBERRyQUENchER (BBQ-650TM)
A dark quencher is a non-fluorescent chromophore that absorbs fluorescence energy from a neighboring fluorophore, thereby preventing emission of fluorescent light.128-53-0 site In Fluorescence Resonance Energy Transfer (FRET), a dark quencher then relaxes to its ground state by emitting energy as heat. In static quenching, e.g., in molecular beacons, the dark quencher forms a ground state complex with the fluorophore, preventing emission of fluorescence until hybridization disrupts the complex.PMID:29939648 Glen Research already offers a variety of quenchers for a wide range of applications. However, quenching at longer wavelengths has always been problematical since molecules absorbing at 600nm tend to have extended p systems that make them very susceptible to degradation by the conditions of oligonucleotide synthesis and deprotection. We are now happy to begin offering several products containing the BlackBerryQuencher (BBQ-650TM). Based on an 8-alkoxyjulolidine structure that is a potent p electron donor, BBQ-650 exhibits a broad absorption profile from 550nm to 750nm, centered at 650nm. This range offers more effective quenching of some of our popular long wavelength dyes like TAMRA, Redmond Red, Cy dyes and DyLight dyes. Moreover, BBQ-650 is stable to regular deprotection, but requires mild deprotection with AMA at room temperature. We offer BBQ-650 products for the 3′ and 5′ termini, as well as BBQ-650-dT for inclusion within the oligonucleotide sequence. BlAckBERRyQuENchER hIGhlIGhTs
exclusively for research and development purposes. They may not be used for clinical or diagnostic purposes and they may not be re-sold, distributed, or re-packaged without prior agreement and consent of Berry & Associates, Inc. Subsequent s.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com