OligonucleotideOligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids can be manufactured as single-stranded molecules with any user-specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, molecular cloning and as molecular probes.
Two-hybrid screeningTwo-hybrid screening (originally known as yeast two-hybrid system or Y2H) is a molecular biology technique used to discover protein–protein interactions (PPIs) and protein–DNA interactions by testing for physical interactions (such as binding) between two proteins or a single protein and a DNA molecule, respectively. The premise behind the test is the activation of downstream reporter gene(s) by the binding of a transcription factor onto an upstream activating sequence (UAS).
X chromosomeThe X chromosome is one of the two sex chromosomes in many organisms, including mammals, and is found in both males and females. It is a part of the XY sex-determination system and XO sex-determination system. The X chromosome was named for its unique properties by early researchers, which resulted in the naming of its counterpart Y chromosome, for the next letter in the alphabet, following its subsequent discovery. It was first noted that the X chromosome was special in 1890 by Hermann Henking in Leipzig.
DNA demethylationFor molecular biology in mammals, DNA demethylation causes replacement of 5-methylcytosine (5mC) in a DNA sequence by cytosine (C) (see figure of 5mC and C). DNA demethylation can occur by an active process at the site of a 5mC in a DNA sequence or, in replicating cells, by preventing addition of methyl groups to DNA so that the replicated DNA will largely have cytosine in the DNA sequence (5mC will be diluted out). Methylated cytosine is frequently present in the linear DNA sequence where a cytosine is followed by a guanine in a 5' → 3' direction (a CpG site).
Protein engineeringProtein engineering is the process of developing useful or valuable proteins through the design and production of unnatural polypeptides, often by altering amino acid sequences found in nature. It is a young discipline, with much research taking place into the understanding of protein folding and recognition for protein design principles. It has been used to improve the function of many enzymes for industrial catalysis. It is also a product and services market, with an estimated value of $168 billion by 2017.
Northern blotThe northern blot, or RNA blot, is a technique used in molecular biology research to study gene expression by detection of RNA (or isolated mRNA) in a sample. With northern blotting it is possible to observe cellular control over structure and function by determining the particular gene expression rates during differentiation and morphogenesis, as well as in abnormal or diseased conditions. Northern blotting involves the use of electrophoresis to separate RNA samples by size, and detection with a hybridization probe complementary to part of or the entire target sequence.
Amplified fragment length polymorphismAFLP-PCR or just AFLP is a PCR-based tool used in genetics research, DNA fingerprinting, and in the practice of genetic engineering. Developed in the early 1990s by KeyGene, AFLP uses restriction enzymes to digest genomic DNA, followed by ligation of adaptors to the sticky ends of the restriction fragments. A subset of the restriction fragments is then selected to be amplified. This selection is achieved by using primers complementary to the adaptor sequence, the restriction site sequence and a few nucleotides inside the restriction site fragments (as described in detail below).
Parkinson's diseaseParkinson's disease (PD), or simply Parkinson's, is a chronic degenerative disorder of the central nervous system that affects both the motor system and non-motor systems. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms become more common. Early symptoms are tremor, rigidity, slowness of movement, and difficulty with walking. Problems may also arise with cognition, behaviour, sleep, and sensory systems. Parkinson's disease dementia becomes common in advanced stages of the disease.
Reverse transcription polymerase chain reactionReverse transcription polymerase chain reaction (RT-PCR) is a laboratory technique combining reverse transcription of RNA into DNA (in this context called complementary DNA or cDNA) and amplification of specific DNA targets using polymerase chain reaction (PCR). It is primarily used to measure the amount of a specific RNA. This is achieved by monitoring the amplification reaction using fluorescence, a technique called real-time PCR or quantitative PCR (qPCR).
Heat shock responseThe heat shock response (HSR) is a cell stress response that increases the number of molecular chaperones to combat the negative effects on proteins caused by stressors such as increased temperatures, oxidative stress, and heavy metals. In a normal cell, proteostasis (protein homeostasis) must be maintained because proteins are the main functional units of the cell. Many proteins take on a defined configuration in a process known as protein folding in order to perform their biological functions.
