Swagatika In this article, I briefly describe mutagenesis and mutagenesis of cloned genes. Mutagenesis Mutagenesis is a process in which an organism changes its DNA. It results in gene mutation. Mutagenesis can be spontaneous or induced. Specified mutations in genes can be engineered and the effects of these mutations can be tasted. The availability of cloned … Read more >>
In this article, I briefly describe the organization of cloned genes. cDNA clones The cDNA clones synthesized using oligo(dT) as a primer, have a defined organization. The exact copy of an mRNA molecule is called a cDNA or complementary DNA. The well-characterized cDNA molecule binds with a befitting vector and the combination (vector containing the … Read more >>
In this article, I briefly explain clonal anergy and its relation with a costimulatory signal. Clonal anergy A state of clonal anergy develops, when a naïve T cell engages its TCR with an antigen presented by an MHC, without a suitable costimulatory signal. It is a state, where the specific T cell clone shows no … Read more >>
In this article, I briefly describe the working of the coinhibitory receptors CTLA-4, PD-1, and BTLA. Coinhibitory receptor Costimulatory and coinhibitory receptor molecules are vital in regulating immune responses to infections. Coinhibitory receptors bind with their ligands and suppress excess immune responses. When T cells get infected, they tend to express coinhibitory receptors and acquire … Read more >>
In this article, I briefly describe costimulatory receptors CD28 and ICOS and how they bind with their ligands. Costimulatory receptors Co-stimulatory signals are required for optimal T-cell activation. T-cell non-responsiveness arises from high affinity TCR-MHC interactions in the absence of functional antigen presenting cells (APCs). It is called T cell anergy. The interaction between specific … Read more >>
In this article, I briefly describe the duplication of retrovirus in a host cell. The enveloped virus-Retrovirus These are enveloped viruses, that belong to the family Retroviridae. A retrovirus is an RNA virus duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. When the virus infects a … Read more >>
In this article, I briefly describe the various methods of DNA sequencing and their applications. DNA sequencing The process of determining the order of nucleotides in DNA is called DNA sequencing. It determines the order of the four bases, i.e., adenine, guanine, thymine, and cytosine. The nucleotide sequence is the base of knowing a gene … Read more >>
In this article, I briefly describe how desiccation, filtration, osmotic pressure, and radiation control microorganisms. Physical methods of microbial control It is necessary to control microorganisms for the prevention of diseases. Microbial growth is controlled either by killing microorganisms or by inhibiting the growth of microorganisms. Microorganisms are generally controlled by the use of physical … Read more >>
In this article, I briefly describe how temperature controls the growth of microorganisms. Microbial control Microorganisms are controlled to prevent transmission of disease and infection. Microbial growth is controlled either by killing microorganisms or by inhibiting the growth of microorganisms. Microbes must be controlled to avoid contamination by their undesirable growth and prevent material deterioration … Read more >>
In this article, I briefly describe restriction enzymes, their recognition sequences, and the frequency of recognition sequences. What are restriction enzymes? The enzyme that cleaves DNA at specific recognition sites, is called a restriction enzyme. These belong to the endonuclease group of enzymes. Identifying and manipulating restriction endonucleases in the 1960s and early 1970s made … Read more >>