7 Best Immunoassays Technologies to Help Complete Your Experiments Faster

Did you know that Berson and Yalow came up with the concept of immunoassays as early as 1959? Since then, immunoassays have evolved consistently through time because of contemporary scientific developments. Therefore, it’s only logical to assume that such assays are going to undergo further changes in the future.

However, you may not be aware of some of the avant-garde technologies that have already changed immunoassays in major ways. The goal has always been to make these assays faster, more sensitive, and require a lesser amount of samples.

In this article, we’re going to look at seven technological advancements that have made immunoassays faster. You have to keep in mind that, in most cases, speed is paired up with increased efficiency as well.

7 Best Immunoassay Technologies to Help Complete Your Experiments Faster:

Western Blotting Using Capillary Electrophoresis (WesCE)

How long did the traditional Western blot take? As long as 2 days! And that too led to the detection of a single protein after more than 48 hours of manual labor. Moreover, 20 to 30 µg of the sample (which is quite a large requirement) was needed to carry on the experiment.

How did Western Blotting Using Capillary Electrophoresis (WesCE) revolutionize this process? Well, by combining the two processes of traditional blotting and capillary electrophoresis, immunostaining is done in the target capillary. This is possible because each capillary contains separate stacking and separating matrices. With this technology, you can automate your westerns from your protein separation to the detection process itself.

Best part? You only need samples of 3uL for each capillary, and the whole process only requires 3 hours to run as many as 96 samples.

Single-cell Western Blotting (scWestern)

A problem that scientists often face with cell-based assays is that most cell populations are heterogeneous. This is why Hughes et al. from UC Berkeley had to come up with a technique that allowed them to measure the protein expression inside each cell. A delicate polyacrylamide gel is prepared using micro-wells of 20 µm diameter. These fit accurately inside a single cell. Then, the scientists perform lysis within each cell in the gel itself. This allowed gel electrophoresis to be carried out. The next job is to immobilize the proteins in the gel matrix with the help of UV light. This is how the immune probing is conducted.

Again, the speed of the experiment is incredible. scWestern can measure the amount of protein in more than thousands of separate cells in not more than 4 to 6 hours.

In-cell Western Blot (ICW)

There are many names for this technique- near-infrared immunocyto blot, cytoblot, and in-cell ELISA. Through in-cell western, the quantity of target protein in a cultured cell is quantified. Less processing is required for in-cell westerns and thus, is more quantitative. Scientists culture suspension or adherent cells in a microplate that is fixed. This combinational is then ministered with as many as two antibodies. After this, this mixture is incubated with secondary antibodies. These antibodies are conjugated with a fluorophore to make them detectable.

This process takes only 5 hours to test more than 96 samples.

Single-cell Western Blotting (scWestern)

A problem that scientists often face with cell-based assays is that most cell populations are heterogeneous. This is why Hughes et al. from UC Berkeley had to come up with a technique that allowed them to measure the protein expression inside each cell. A thin polyacrylamide gel is prepared using micro-wells of 20 µm diameter. These fit accurately inside a single cell. Then, in the gel itself, the scientists perform lysis. This allowed gel electrophoresis to be carried out. The next job is to immobilize the proteins in the gel matrix with the help of UV light. This is how the immune probing is conducted.

Again, the speed of the experiment is incredible. scWestern can estimate the amount of protein in more than thousands of separate cells in not more than 4 hours.

Multiparameter Flow Cytometry

Flow cytometry refers to the process through which individual cells can be accurately characterized in a population. You can separate the other sub-populations but this is highly dependent on the cell parameters that need to be measured. Multiparameter flow cytometry allows the measurement of as many as 50 parameters across ten laser wavelengths. This is the process through which the highest of parameters can be witnessed. This allows the study of complex or rare cell types.

Mass Cytometry (CyTOF)

Mass cytometry employ labeled probes which are made of heavy metal to reduce the signal overlap. This leads to an increase in the parameters that can be witnessed. You can detect up to 100 parameters using this method.

Multi-Array Assay Technology (Meso Scale Discovery)

In this process, SULFO-TAGTM labels are used which emit light once electrochemically stimulated using electrodes on the microplates. This technology involves the use of patterned arrays as well. Therefore, you can detect multiple analytes inside a single well. The overall sensitivity is improved and you don’t need repeated washes.

Nanobodies/sdAbs

Nanobodies are also known as single-domain antibodies or sdABs. They are fragments that have been derived from antibodies of camels, sharks, llamas, or alpacas. The specialty of these nanobodies is that they contain only a single domain. Thus, they are only about half the size of a regular single-chain variable fragment. These nanobodies are ideal for in vivo immunoassays. They can also easily bind to epitopes that cannot be accessed through regular antibodies.

In Conclusion

There are a lot of other modern technologies that have improved the efficiency of ELISA assays. However, this article focuses on those that improve the speech and sensitivity of the immunoassays. SIMOA and immuno-PCR are some other techniques that have revolutionized bioassays.

To know more – Click Here