Surface Plasmon Resonance (SPR) has revolutionized the way of measuring the binding in molecules, in real-time, without the use of labels.
If a clinician is keen on measuring the antibodies generated in a serum, then they could use the SPR technique to make a count and analyze the interactions between compounds like proteins, antibodies, and even DNA in the molecules.
Introduction to Surface Plasmon Resonance (SPR)
Enzyme-linked Immunosorbent Assay (ELISA) can be developed in any place, mostly in a laboratory. But there exists another possible technique that can take that measurement and it’s called SPR.
Surface Plasmon Resonance is an optical refractive technique that measures the binding of molecules without the use of labels. Since data of association and dissociation can be collected in real-time, SPR enables parallel analysis of both the binding affinity and the binding kinetics between the molecules. Clinicians also use this data to assess the stability and strength of the binding interaction between which molecules, when, and why too.
SPR works by noting the changes seen on a refractive index of a detector when polarized light is sent through a prism to the bottom of a metal surface. The top of this surface has biomolecules like proteins and RNA immobilized to it.
When the light refracts through the prism to the metal surface, the electrons absorb some light at an angle called resonance angle, which brings about a slight shift in the direction of the light; due to binding to the surface. The shift is tracked on the detector and it works as an SPR signal. The signals are plotted each time it changes without labels.
Applications of Surface Plasmon Resonance (SPR) in Clinical Research
The measuring of the binding between biochemicals is critically useful in many sectors of pharma and has been used by countless drug manufacturers throughout the years. SPR makes the process easier and outperforms ELISA in many ways.
Labs can develop SPR methods, when required, on the signals to measure the concentration of protein analytes, which are necessary for the development of many prescription drugs. SPR helps measure the antibodies, detect anti-drug antibodies with the binding strength and movement signals in the drug development process.
Otherwise, the usual commercially available SPR can check how the patient may respond to the drug on the basis of which the physician can give a prognosis for their ailment with respect to the course drug movement, or detect how their body reacts to antigens—in the setting of autoimmune diseases.
SPR is economically and optimally more accessible than ELISA and significantly less time-consuming. SPR doesn’t require any labeling, and if it did as ELISA did, the process would require additional skill and power and may interfere with the binding or stability of antibodies or analytes.
Additionally, SPR also does not require a lot of preparation or sample volume; the biomolecules can be diluted and arranged on the SPR surface and subsequently immobilized conveniently. Due to the real-time data, it provides, including kinetic and affinity binding, the signals can be caught quickly and can be interpreted just as swiftly.
Challenges of Surface Plasmon Resonance (SPR) in Clinical Research
Convenient as it is, SPR can be a struggle to adapt as a steady method. It isn’t ideal to measure non-specific binding as it desensitizes the assay, which matters when dealing with serum. This can be corrected using dilution or the addition of other detergents to the buffer and the samples.
Other than analytical challenges, SPR is harder to adopt because of how expensive it is to afford the instrument. Only a few companies manufacture it either and SPR has been noteworthy in literature only so far, making it inaccessible for everyone to use.
