In vitro diagnostic (IVD) applications frequently make use of nanoparticles as solid-phase carriers for a given capture molecule. In order to be utilized in this manner, nanoparticles must first be coated, thereby attaching the capture molecules to the particles. There are notable differences in the way that different types of particles are coated, and this will be a significant factor in the decision to utilize one particle over another in a given assay, for example, streptavidin beads or latex particles.
As you can learn in our protein purification handbook, production techniques of recombinant proteins offer multiple options when it comes to available hosts; in other words, the organisms that incorporate the gene of the protein of interest and express it correctly.
Because of their significantly increased surface area and their ease of manipulation, in vitro diagnostic (IVD) assays commonly make use of nanoparticles, typically utilizing them as solid surface carriers for capture molecules. There are a number of particles that can be utilized in IVD assays. White latex particles, for instance, have traditionally been used in diagnostic tests such as immunoturbidimetry and nephelometry assays, but we find other interesting examples such as streptavidin beads.
The traditional way to check whether a biomagnetic separation process is complete is by sight. The technician/researcher looks at the suspension: at the beginning of the process, the suspension is homogenous and opaque, but when the separation process is complete, the magnetic beads are left on the walls of the vessel and the supernatant is transparent. When the suspension is ‘transparent’, the technician stops the process by extracting the supernatant, leaving the magnetic beads in the bottle.
As you will learn in our protein purification handbook, proteins are biomolecules of great value to humans, since they have a wide variety of uses in different sectors. They can have therapeutic (such as in insulin cases or blood clotting factors), industrial (such as the lipases that are included in detergents that degrade grease stains) or biotechnological (in the case of certain toxins that are used as pesticides) applications. They also have an extensive application in the research field, in cases when they can be used to study the molecular mechanisms of many diseases, find new drugs, or elucidate tridimensional structures, among others.
Human beings extensively use proteins for different purposes such as health, industrial production or food. Nevertheless, most of these proteins come from natural sources that do not produce them in sufficient quantities for human use; therefore, we turn to the use of recombinant proteins. Such proteins are obtained from organisms (called “host organisms”) that do not produce them naturally, and in which the gene of the protein of interest is incorporated.
Sometimes during biomagnetic separation in a magnetic separation rack, different steps in the process require using different volumes. For example, if you have produced a ‘mother batch’ of magnetic beads and this large batch needs to be aliquoted so that each aliquot of beads can be uniquely coated, you will need the ability to move easily between volumes.
Although separation time may be one of the most obvious parameters to validate in your magnetic separation rack production, it is certainly not the most critical. Classical magnetic separation rack use non-homogeneous magnetic separation. When scaling up production on these devices, larger volumes can lead to longer and longer separation times.
Any small magnetic separation rack (i.e. the types used to develop a prototype product before scaling up) generates magnetic fields that decay rapidly with distance. However, scaling up the process can be problematic because the size of the classical magnetic separation rack itself grows rapidly with desired batch volume. Because the magnetic field profile and the magnetic force are not the same in a larger device, the safety of users and the safety of ancillary equipment can become a serious issue.
Electromagnets are the classical way to generate intense magnetic fields. If you apply the electrical current across a coil, the magnetic field is quite small. But if you wrap the coils around an iron yoke, you can generate much stronger magnetic fields. Unfortunately, if you need to scale up a magnetic separation process, you also need to increase the electrical power to the magnetic separation rack and the amount of iron and copper used for the coil.
