Protein Expression Prokaryotic cells E. coli

Western blotting is a widely used technique to size separate proteins from a pool of cell or tissue lysates. The technique has 4 major steps: a) gel electrophoresis, b) blocking and treatment with antigen specific antibody, c) treatment with secondary antibody and finally d) detection and visualization. Though western blotting is a widely used technique, detection of specific proteins depends on several factors, the major ones are antibody concentration, incubation time and washing steps. Key points for obtaining clean blots are: always prepare fresh buffer solutions and optimize antibody concentration. Given the advent of high-throughput protein analysis and a push to limit the use of lab consumables, onestep antibodies are developed which recognise protein of interest and also contain a detection label.

RNAi or RNA interference is a common method to suppress gene expression in vitro/in vivo by utilizing the inherent microRNA machinery, without introducing a total gene knockout. miRNA is the inherent gene silencing machinery which can have more than one mRNA target, whereas siRNA can be designed to target a particular mRNA target. By design, both siRNA and miRNA are 20-25 nucleotides in length. The target sequence for siRNAs is usually located within the open reading frame, between 50 and 100 nucleotides downstream of the start codon. There are two ways in which cells can be transfected with desired RNAi: 1. Direct transfection (with calcium phosphate co-precipitation or cationic lipid-mediated transfection using lipofectamine or oligofectamine), and 2. Making RNAi lentiviral constructs (followed by transformation and transduction). Lentiviral constructs are time-consuming, but provide a more permanent expression of RNAi in the cells and consistent gene silencing. Direct transfection of oligonucleotides provides temporary genetic suppression. Traditional methods like calcium phosphate co-precipitation have challenges like low efficiency, poor reproducibility and cell toxicity. Whereas, cationic lipid-based transfection reagents are able to overcome these challenges, along with applicability to a large variety of eukaryotic cell lines.

Get tips on using Penta·His Biotin Conjugate to perform Protein tag Detection of His-tagged proteins

Get tips on using PhosphoProtein Purification Kit (6) to perform Protein tag Purification of phosphorylated proteins

Get tips on using Qproteome Mitochondria Isolation Kit to perform Protein enrichment Mitochondria

Get tips on using Gal-Screen™ β-Galactosidase Reporter Gene Assay System for Mammalian Cells to perform Reporter gene assay β-galactosidase substrates - yeast, Yarrowia lipolytica

Get tips on using CelLytic™ M to perform Protein isolation Bacteria - Staphylococcus aureus

Get tips on using 3D-Gene® Mouse miRNA Oligo chip (ver.21) to perform Microarray Gene expression arrays - Mouse liver tissue Cyanine-3-CTP

Get tips on using Galacto-Star™ β-Galactosidase Reporter Gene Assay System for Mammalian Cells to perform Reporter gene assay β-galactosidase substrates - MCF-7 human breast cancer