DNA Damage Assay Human bronchial epithelial cells (hBE)

Isolating RNA from tissues and paraffin-embedded tissue samples can be challenging due to cross-linking of biomolecules and fragmented nucleic acids. The best solution is to slice the tissues into smaller pieces and make a homogenate solution (using tissue homogenizer or grinding liquid nitrogen frozen samples) in presence of RNAse inhibitors. The homogenization process should be carried out on dry ice to maintain the integrity of RNA.

Get tips on using Attractene Transfection Reagent to perform DNA transfection Mammalian cells - Immortalized cell lines OVCAR-3

Get tips on using Lipofectamine® LTX Reagent to perform DNA transfection Mammalian cells - Immortalized cell lines Neuro2a

Get tips on using Lipofectamine® LTX Reagent to perform DNA transfection Mammalian cells - Immortalized cell lines BXPC3

Get tips on using EpiTect Fast 96 Bisulfite Kit to perform Bisulfite DNA Modification Cell lines / primary cells

Get tips on using EpiTect Fast Bisulfite Kit (10) to perform Bisulfite DNA Modification Cell lines / primary cells

Human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) have been greatly used for studies on embryonic development and cell differentiation.iPSCs provide a stable source for either self-renewal or differentiation into suitable cells when cultured in a particular environment. Pluripotent cell culture was originally started by deriving cells from inner cell mass (ICM) from pre-implanted blastocysts, these were called embryonic stem cells. These cells after isolation can be grown on traditional extracellular matrices (like mouse embryonic fibroblasts, MEFs) or feeder-free culture systems. DMEM/F12 has been the most commonly used basal media in the culture of pluripotent cells. These cells are cultured at normal atmospheric oxygen levels, 21%, however, some studies have proposed that 4% oxygen tension may be better for hESC growth. Higher D-glucose concentration (4.2g/l) and osmolarity (320mOsm) that mimics the natural environment of embryonic tissue are optimal for the growth of hESCs. Supplements like N2 and/or B-27, in the presence of growth factors like bFGF, have been shown to increase pluripotency of these cells. bFGF, FGF2 and other ligands of receptor tyrosine kinases like IGF are also required or maintain self-renewal ability of these cells. TGF𝛃1, by its activation of SMAD2/3 signalling, also represses differentiation of iPSCs. Other compounds like ROCK inhibitors reduce blebbing and apoptosis in these cells to maintain their clonogenicity. However, an inhibitor for LIF (leukaemia inhibitory factor, which is one of the pluripotent genes) has an opposing effect. Therefore, it is important to understand the culture conditions and media composition that affect downstream signalling in hESCs or iPSCs that may lead to their differentiation.

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. When using oligos, the ideal concentration lies between 10-50nM for effective transfection.

Get tips on using Live/Dead Cell Double Staining Kit to perform Live / Dead assay mammalian cells - L29 mouse fibroblast

Get tips on using Purified Mouse Anti-Human MSH-2 Clone G219-1129 (RUO) to perform Immunohistochemistry Human - MSH2