Abstract: The proprietary cell-permeable nucleic acid probe SYTO® 9 is commonly used in microbiology as either a standalone dye or in combination with propidium iodide (PI) in bacterial viability assays. The usefulness of SYTO® 9 in general overcomes the negative aspects such as high cytotoxicity, but cell-permeable fluorophores such as MycoLight™ Green JJ98 and MycoLight™ Red JJ94 provide alternatives with equivalent sensitivity and fewer downsides. MycoLight™ Green JJ98 in particular shows near-ideal results in combination with PI in bacterial viability assays, with highly similar spectra to SYTO® 9 and slightly improved performance with common instrumentation settings of both flow cytometers and fluorescence microscopes.
Abstract: A novel dual excitation/emission fluorescent probe has been developed for specific and sensitive determination of intracellular pH in cellular processes. The present study explores the effectiveness of RatioWorks™ pH 165, AM as a pH-sensitive fluorescent indicator by analyzing the spectral characteristics in HeLa cell lines with pH measurements using a fluorescence microplate reader. Standard buffers in the range of pH 4-10 were used in analyzing the excitation/emission spectrum of the dye. The pH measurements were determined using the ratio of the emission and excitation intensities of the dye at dual wavelengths (λ ex/ λ em : 497nm/594nm and 578nm/654nm, respectively). Cell cytotoxicity was evaluated using CCK-8 assay at an incubation period of 120 min post WST-8 addition. The fluorescence response of RatioWorks™ pH 165, AM obtained with Cy3/TRITC and Cy5 filters at different pH regions provide evidence for accurate pH measurements of intracellular organelles as well as low cytotoxic nature of the probe. Furthermore, in contrast to other fluorescein derivatives, RatioWorks™ pH 165, AM exhibits response in the red and far red spectrum, making the probe an ideal dual excitation/emission fluorescence pH sensor for multiplex immunoassay technologies involving GFP. RatioWorks™ pH 165, AM proves to be a competitive pH indicator among other fluorescent-based technologies.
Abstract: Therapeutic monoclonal antibodies (mAbs) represent a promising class of biopharmaceutical tools revolutionizing the treatment landscape of immunological disorders, reversal of drug effects, and cancer therapy. Since the late 1990s to 2018, the total number of approved therapeutic mAbs by the US FDA reached 64, with eleven being approved in 2017. This growing interest in therapeutic mAb technologies has sparked a noteworthy need to enhance and expand the range of available tools for diagnostic and therapeutic evaluation of mAbs in pre-clinical models. To satisfy these demands, scientists at AATBioquest have developed a plethora of ReadiLink™ conjugation technologies to assist researchers in developing custom-labeled fluorescent mAb conjugates for use in imaging and flow cytometric target identification and validation studies, as well as determining viable lead candidates.
Abstract: The impact of any protein in cells is widely studied by over expressing a protein of interest and investigating the biomolecular alterations that occur due to the overexpression of that protein. These studies are undertaken to better understand the functionality of vital proteins, such as tumor suppressor proteins or oncogenes. The process of overexpressing proteins is mainly facilitated using a lipid based DNA delivery system which passively delivers DNA into the cells for subsequent translation into protein. In this proposed study, the transfection efficiency of Transfectamine™ 5000, Lipofectamine™ 2000 and Lipofectamine™ 3000 were compared. Comparative analysis revealed a 2-3 fold increase in transfection efficiency with much lower cytotoxicity when using Transfectamine™ 5000 over its counterparts. Additionally, agonist-stimulated calcium responses with Transfectamine™ 5000 transfected cells was much more pronounced than Lipofectamine™ 2000 and Lipofectamine™ 3000 transfected cells.
AATBioquest‘s Mycolight™ Bacterial Viability Assay Kit provides two-color fluorescence assay of bacterial viability in both gram-positive and negative bacterial cell. The kit utilizes the mixture of our green fluorescent nucleic acid stain MycoLight™ Green and the red-fluorescent nucleic acid stain propidium iodide.
RatioWorks™ PH165 AM is a novel fluorescent probe that can be used to measure intracellular pH in live cells. It shows pH-dependent fluorescence spectra. Its dual excitation and dual emission make it a unique ratiometric pH probe for analyzing live cells.
ReadiLink™ Rapid Antibody Labeling Kits utilize fluorophores coupled to an amine-reactive moiety (succinimidyl ester). These reactive dyes selectively bind to aliphatic amines of proteins forming carboxamide bonds. Once formed these carboxamide bonds are extremely stable, ensuring no dissociation between label and protein.
Transfectamine™ 5000 Transfection Reagent is a powerful and versatile transfection reagent for the introduction of nucleic acids into eukaryotic cells, or more specifically, into animal cells. It can effectively transfect a variety of payloads into a variety of adherent and suspension cell lines. It can be used for plasmid DNA transfection as well as siRNA- and shRNA-based gene knockdown experiments and gene expression studies.