What are the advantages of transfection methods?4 answersTransfection methods offer several advantages in gene delivery. Non-viral chemical-based methods provide high efficiency, low cost, and reduced cell toxicity compared to virus-based techniques. mRNA-based vectors allow fast transgene expression, gene expression in nondividing cells, and high cell survival rates without the need to disrupt the nuclear envelope. Cationic polymers, among non-viral carriers, are attractive due to their low toxicity and immunogenicity, offering versatility in chemical structure modification. Optimizing transfection efficiency is crucial for gene therapy studies, and a flow cytometric method enables quantification of cellular toxicity, nucleic acid uptake, and protein expression, enhancing data robustness and reducing assay costs. The choice of transfection method depends on the experimental design and objectives, with each method having its own set of advantages and disadvantages.
What is usage of phospha-Michael reaction?5 answersThe phospha-Michael reaction is a versatile synthetic tool used for the construction of various complex molecules. It involves the addition of phosphorus nucleophiles to electron-deficient alkenes, providing chiral organophosphorus compounds efficiently. This reaction has been successfully applied to α-fluorinated acrylates, yielding products with C-P and C-CFY2 bonds in good yields and diastereoselectivities. Additionally, the phospha-Michael addition has been utilized in the synthesis of chiral chromene derivatives with high reactivity and excellent enantioselectivity, producing chiral products with high yields and enantiomeric excess. Furthermore, a biocatalytic method utilizing the phospha-Michael reaction has been developed for the synthesis of pharmacologically relevant β-phosphonomalononitriles, showcasing excellent yields, mild reaction conditions, and sustainability.
What is transfection?4 answersTransfection is the process of introducing foreign nucleic acids into eukaryotic cells. It is a powerful method used in various fields such as studying gene function, investigating gene expression and protein function, and manufacturing clinical-grade recombinant biologics. Transfection methods can vary, including biological methods such as enveloping the DNA inside a virus or bacteria, chemical methods such as coating or neutralizing the negative charge of the DNA, and physical methods such as propelling the DNA through the membrane by creating holes. Transfection efficiency is an important parameter that affects the productivity of biologics, and optimization of transfection conditions can be achieved using mathematical methods like Design of Experiments (DoE). Transfection is also relevant in bacterial systems, where it is known as transduction and is a mechanism of horizontal gene transfer.
What is shrna transfection?4 answersshRNA transfection is a technique used to introduce short hairpin RNA molecules into cells in order to silence specific genes. It can be performed in cultured mammalian and insect cells. The shRNA molecules are typically expressed from a DNA template using a promoter, such as the U6 small nuclear RNA promoter. The DNA template is transcribed into shRNA molecules, which are then processed by enzymes like Dicer to form active small interfering RNAs (siRNAs). These siRNAs can bind to target mRNA molecules and induce their degradation or translational repression, leading to gene knockdown. shRNA transfection can be used for functional knockdown analyses in various cell line models. It has been applied in studies related to oncogenic pathways, spermatogenesis function, and gene therapy for cancer treatment.
How does a FRET calcium ion biosensor work?5 answersA FRET calcium ion biosensor works by utilizing a fluorescent protein-based biosensor that can track the movement of calcium ions within living systems. These biosensors consist of targeting domains, sensing domains, and reporting domains, which allow them to detect and report ionic or voltage responses to contact with bioactive agents. The biosensors can be introduced into cells that have been reprogrammed to represent experimental or pathologic cells of interest, and these model cells can then be contacted with potential bioactive agents to determine their activities. The working mechanism of a specific FRET calcium ion biosensor involves an excitation ratiometric green fluorescent protein-based biosensor called GEX-GECO1. This biosensor undergoes an ultrafast excited state proton transfer (ESPT) reaction upon photoexcitation, and the presence of calcium ions leads to distinct populations with different ESPT time constants.
Why is P1 virus used in transduction experiments?4 answersBacteriophage P1 is used in transduction experiments because it is capable of efficiently transducing genes into different strains of Escherichia coli, including uropathogenic strains. P1 phage has a broad host range and can infect and promote transduction in various bacterial species, making it a useful tool for genetic studies. P1(S') tail fiber, a variant of P1 phage, has been shown to transduce phagemid DNA into specific bacterial strains, such as Shigella flexneri and Escherichia coli, efficiently. This ability of P1(S') to deliver DNA sequences into clinically relevant bacterial strains, including those that are difficult to culture, makes it valuable for genetic manipulation and the study of bacterial genetics. Overall, the wide host range and efficient transduction capabilities of P1 phage make it a versatile tool for horizontal gene transfer and genetic manipulation experiments.