The sandwich ELISA is a type of Enzyme-linked immunosorbent Assay that uses two antibodies: a capture antibody and a detection antibody. It is called a sandwich because your antigen is bound between antibodies. The purpose of any ELISA is to detect the presence of a target antigen in a sample. In a sandwich ELISA the target antigen is bound between a capture antibody and a detection antibody. The capture antibody is immobilized on a surface, while the detection antibody (conjugated to an enzyme or fluorophore label) is applied as a last step before quantitation.
Nucleic acids refer to biomolecules composed of nucleotides. A nucleotide is the name of a nucleic acid monomer which consists of a 5-carbon sugar base bound to a nitrogenous base and a phosphate group. The type of nucleotide is based on the type of nitrogenous base that is bound. For deoxyribonucleic acid (DNA) the four predominantly found bases are guanine, adenine, cytosine, and thymine. For ribonucleic acids (RNA) the four main bases are guanine, cytosine, thymine and uracil. Both DNA and RNA are part of the central dogma of molecular biology and are studied extensively. Nucleic acids are also used for research and therapeutic purposes. In order to study and use nucleic acids, it is important to have a system of nucleic acid labeling. Nucleic acid labeling can also be used to track nucleic acids.
Importance and uses of cell isolation
There are many different types of cells, there are 200 types of cells in the human body alone. To give an example overview of the types of cells, there are red blood cells, white blood cells, muscle cells, bone cells, nerve cells and many more. In order to study all the individual cell types, scientists use cell isolation to get specific cells alone to study them. There are many reasons to study a cell, from the internal to external mechanisms. For example, some researchers study the motility of cells. They explore how the cells move and how the cytoskeleton plays a role in those movements. Experiments can also be done that give the cells certain molecules and the effects of those molecules on motility can be observed. Scientists are also interested in studying how cells divide and study if certain gene mutations cause differences in how cells divide. For those interested in clinical reasons for cell isolation, it is important to do cell isolation for blood to separate the components into useful therapeutic components.
The ability to isolate cells is important in both clinical and research settings. The goal of cell separation is to isolate one population of cells that are of interest. There are several reasons for performing cell separation, some examples are interest in studying a cell type or using it for therapy such as T-cell therapy. Some researchers are interested in cell separation to be used for creating hybridoma cell lines or for testing drugs in vitro and seeing the effect of the drugs on cells. There are many available techniques for cell separation. These techniques differ in specificity of cell selection, cost of equipment, time to complete, technology needed, and skill required. Cell separation based on cell density is rapid and inexpensive but is unspecific. Still, it is a fundamental technique that is commonly used in a variety of settings for general cell separation.
mRNA purification: how mRNA vaccines work
The letters “mRNA” are heard everywhere lately. The mRNA vaccine has been widely distributed in response to COVID-19. The mRNA in the vaccine enters cells in the body where the cell machinery can translate the mRNA into the Spike surface protein of the coronavirus. The body recognizes the spike protein as an antigen and produces antibodies against it. When infected with the actual virus later on, the immune system has a base defense system, antibodies, ready to more specifically remove virus.
An antigen is defined as anything that causes an immune response in another organism. This immune response can be a simple increase of inflammatory factors, or it can be an activation of the adaptive immune system and creation of antibodies. Antibodies have two or more specific paratopes, or antigen recognition sites, that identify and combat the invading antigen. The number of antigen recognition sites is dependent on the antibody class. The word “antigen” can also refer to any protein of interest detected by a bioassay or biodetection platform. In the case of a bacterial antigen, we are referring to surface proteins, lipopolysaccharides, and peptidoglycans on the bacterial cell wall; these structures help bacteria invade other organisms by gaining access between epithelial cells. While surface structures help bacteria infect other organisms, they are also a detriment to the bacteria because they also serve as a unique tag that antibodies and bacteriophages can recognize. Bacteriophages are viruses that attack bacteria. Both antibodies and phages are being used by scientists to develop new biodetection and biosensing platforms for rapid detection of bacterial antigens in the environment and in clinical samples.
Overview of cell biology and its importance
The main two categories of cells are prokaryotic and eukaryotic cells. Prokaryotic cells are what make up bacteria and archaea while eukaryotic cells make up organisms of the domain eukaryota. The inside of the prokaryotic cell houses it’s genetic material, DNA, in a region called the nucleoid region. There are also ribosomes within the central region of the bacteria. The next layer is the plasma membrane, a bi-lipid layer like you will see for eukaryotic cells. Unlike eukaryotic cells, prokaryotic cells will have a cell wall and a capsule surrounding the cell membrane. The eukaryotic cell is surrounded by a lipid membrane, and has membrane-bound organelles. The genetic material, DNA, is stored in the nucleus which is a membrane bound organelle. In research, many different types of cells are used. Bacterial cells are used in protein purification to grow a plasmid to express a protein of interest. You can read about this in our article protein expression and purification. Many types of Eukaryotic cells are used to do in vivo studies. Depending on your research interests, you might use muscle cells, or skin cells, or cancer cells.
The capability of 1 μm and 2.8 μm magnetic particles to intracellularly deliver cargo proteins
In a recently published paper, researchers of the CIBER-BBN and the University Autonoma de Barcelona demonstrated that magnetic microparticles of 1 and 2.8 μm of diameter, in combination with an appropriate magnetic force, could greatly decrease the time needed to interact with and enter target cells, a clear advantage over other types of drug delivery systems.
Enzymes: an overview
Enzymes are proteins with the ability to catalyze chemical reactions. We have several articles you can read to learn more about proteins, their uses, and isolating them for research and clinical purposes. Check out our protein isolation article if you are thinking about how to best purify your protein of interest or read our protein assay article to learn more about working with proteins. Enzymes are particularly interesting and useful due to their catalytic activity. The molecule that goes into the enzyme for manipulation is called the substrate. You will often see this interaction called the “lock and key” interaction as the substrate has to fit just right into the pocket of the enzyme for it to work properly (enzymes are highly specific!), the way a key is very specific to the lock it goes into.
Protein A
Protein A is the name of a protein found on certain bacterial cell walls. The protein has a binding site for Immunoglobulin G (IgG). This ability to bind IgG has been protein A a useful tool for research laboratories. Protein A has many uses. If conjugated to a detectable marker, such as a fluorescent marker or an enzyme, it can be used to detect antibodies. Protein A can also be used to purify total IgG from a solution. Also it can be used for immunoprecipitation as a way to purify a molecule of interest using a solid support system.
