ELISA is the most common ligand-binding assay used in the detection and quantification of substances from biological matrices. From medical screening to detecting food allergens, ELISA is used in almost all biological research. Due to its sensitivity and versatility, ELISA can easily be modified to suit several bioanalyses. Since the early time of ELISA development, it has witnessed newer applications that were never possible before. ELISA lab services are bioanalytical laboratories specialized in performing several pivotal techniques such as ELISA, HPLC, and LS-MS. Let us focus on how these labs perform and carry out ELISA assays to support various aspects of drug development.
The use of ELISA assays
When it comes to cost-effective and simple screening methods, there is no better option than ELISA assays. Other methods may seem faster or cheaper on a sample to sample basis, but when estimation is scaled up to higher volumes, ELISA offers best-in-class speed and cost-efficiency. The ELISA assay equipment is relatively inexpensive and can easily accommodate larger volumes without the need for any additional set-ups.
ELISA assays can be easily performed in a wide range of analytes and matrices, including blood, hair, serum, plasma, urine, oral fluid, and other forensic samples. Moreover, studies have also used ELISA with less common matrices such as fingernails and breast milk. It is particularly advantageous when it comes to elisa service. ELISA method validation is crucial if laboratories want to acquire research contracts from large pharmaceutical companies. ELISA assay validation is comparatively simple and easy to achieve, making it an ideal choice of detection assay.
How is ELISA performed, and how are its results interpreted in the context of drug development?
The basic principle of an ELISA assay is the combination of antigen-antibody reaction and measuring the activity colorimetrically. Once the substrate is modified by the enzymatic reaction, it changes color, and the color change is measured and converted into numeric values. Depending on the type of antigen-antibody combination, ELISA assay can be a direct, indirect, sandwich, or competitive ELISA. Due to higher specificity compared to other ELISA’s, sandwich ELISA is the most common type of ELISA used in clinical research. Following is a traditional ELISA protocol:
First, the choice of antibody is immobilized in an ELISA plate. The plate is incubated for around 15-18 hours for complete immobilization of the antibody. Post-incubation, the diluted antibody is removed with the help of a washing solution. The washing step is one of the important tasks performed at regular intervals in an ELISA protocol. Then a blocking buffer is added to each well to minimize the random binding of target proteins. The next step involves the addition of detection antibodies followed by the addition of enzyme-linked secondary antibodies. A substrate is then introduced in the reaction mixture so that color develops, which can then be measured colorimetrically.
Appropriate ELISA validation is critical in the accurate quantification of the analyte of interest. From a clinical research perspective, ELISA assays can be optimized for several components of the drug development cycle, which includes pharmacokinetics studies, nonclinical toxicology studies, immunogenicity testing assays, cell-based assays, and so on.
Thus, ELISA assays are one of the most simple but widely used bioanalytical assays in the drug discovery and development space.