siRNA / RNAi /miRNA transfection Human Cells Primary splenocytes

Get tips on using Mammary Epithelial Cell Growth Medium to perform 3D Cell Culture Media Human primary breast ephitelial cells-organoids

Get tips on using Mammary Epithelial Cell Growth Medium to perform 3D Cell Culture Media Human primary breast ephitelial cells-Mammospheres

Get tips on using Gibco DMEM/F-12, HEPES to perform 3D Cell Culture Media Human primary breast ephitelial cells-organoids

Get tips on using Dual-Luciferase® Reporter Assay System to perform Reporter gene assay luciferase - primary human endometrial stromal cells

Reporter gene assays enable high sensitivity measurement of gene expression and cell signaling through the addition of bioluminescent genes into target cells. One of the major challenges is to make a specific construct that has no responses other than those related to the signaling pathway of interest. This can be achieved by selecting highly specific reporter constructs containing only defined responsive elements and a minimal promoter linked to reporter enzymes such as luciferase

An alternative to culture-based cell death detection is an assessment of other cell viability indicators using fluorescent dyes, including membrane potential and membrane integrity. Live/Dead assays differentiates live and dead cells using membrane integrity as a proxy for cell viability and are based on a fluorescent staining procedure followed by detection using flow cytometry. However, samples preparation for such flow cytometry-based techniques could be challenging. Cell harvesting by trypsinization, mechanical or enzymatic cell disaggregation from tissues, extensive centrifugation steps, may all lead to preferential loss of apoptotic cells. To overcome this strictly follow manufacturers instruction of the detection kit.

An alternative to culture-based cell death detection is an assessment of other cell viability indicators using fluorescent dyes, including membrane potential and membrane integrity. Live/Dead assays differentiates live and dead cells using membrane integrity as a proxy for cell viability and are based on a fluorescent staining procedure followed by detection using flow cytometry. However, samples preparation for such flow cytometry-based techniques could be challenging. Cell harvesting by trypsinization, mechanical or enzymatic cell disaggregation from tissues, extensive centrifugation steps, may all lead to preferential loss of apoptotic cells. To overcome this strictly follow manufacturers instruction of the detection kit.

As autophagy is a multi-step process which includes not just the formation of autophagosomes, but most importantly, flux through the entire system, including the degradation upon fusion with lysosomes, which makes it quite challenging for detection. There are several methods for detection in mammalian cells, including immunoblotting analysis of LC3 and p62 and detection of autophagosome formation/maturation by fluorescence microscopy, Currently, there is no single “gold standard” for determining the autophagic activity that is applicable in every experimental context, hence it is recommended to go for the combined use of multiple methods to accurately assess the autophagic activity in any given biological setting.

Short hairpin or small hairpin RNA (shRNA) is artificial RNA, which has a hairpin loop structure, and uses inherent microRNA (miRNA) machinery to silence target gene expression. This is called RNA interference (RNAi). These can be delivered via plasmids or viral/bacterial vectors. Challenges in shRNA-mediated gene silencing include 1. Off-target silencing, 2. Packaging shRNA encoding lentivirus, and 3. Stable transduction in cells. RNAi has been designed to have anywhere from 19-27 bs, but the most effective design has 19 bp. In case commercial shRNAs are not available, potential target sites can be chosen within exon, 5’- or 3’ UTR, depending on which splice variants of the gene are desired. One should use the latest algorithms and choose at least two different sequences, targeting different regions, in order to have confidence in overcoming off-target effects. A BLAST search after selecting potential design will eliminate potential off-target sequences. For the second challenge, sequencing the vector using primers for either strand (50-100 bp upstream) is suggested, along with using enzymatic digestion on agarose gel for the vector. Next, once the shRNA-containing vector is packaged in a virus, it is important to check the viral titer before transduction. Finally, using a marker in the lentiviral vector (fluorescent protein or antibiotic resistance), along with qPCR for target gene expression can help in determining the efficacy of transduction and shRNA on its target site.