Types of Immunoassays Methods in Pharmaceutical Analysis 

An immunoassay is referred to as a test that is undertaken to detect or measure the concentration or the presence of an analyte in your eye . Thus, you are more likely to produce such antibodies due to small molecules or an infection. This analyte could also be a huge protein. Based on the needs of the end-user, the assays could also be applied in any format. Immunoassays are used mostly in all the necessary pharmaceutical areas like clinical pharmacokinetics, therapeutic drug monitoring, pharmaceutical industries, bioequivalence studies in drug discovery, and the diagnosis of diseases.

However, the key component like influenza nucleoprotein is specifically designed to detect the analyte at a low concentration. Also, there are many immunoassay platforms available for you to measure the analyte’s concentration. There are various types of immunoassays methods that play great importance in pharmaceutical analysis. In this article, we will discuss the different types of Immunoassays methods that are used in the Pharmaceutical analysis.

Immunoassay methods used in pharmaceutical analysis 

There are different types of immunoassay methods that are used in pharmaceutical analysis. The major immunoassay test is as follows: 

  • Radioimmunoassay (RIA)

It is considered the oldest and the most sensitive immunoassay test. RIA makes use of the antibodies to measure and detect the presence of antigens such as hormone levels in your blood. Radioactive elements are those which are parts of the ancient. When an antigen sample of interest is mixed with the non-radioactive agents, then even the non-radioactive antigens are substituted as the radioactive antigens. Also, the major benefit of RIA is that the measurement of compounds is quite sensitive and precise in the biological fluids.   

  • Fluoroimmunoassay (FIA)

FIA has been categorized into two categories homogeneous and heterogeneous assays based on the need for a separation step. In the homogeneous FIA, the antibody-bound analyte doesn’t need to be separated before the fluorescence measurement from the free analyte.

Whereas a heterogeneous method was designed to measure the fluorescent signal and for determining the complete thyroxine in the human serum. The heterogeneous methods are not available at current for analyzing the pharmaceutical compounds.

Therefore, both of these methods are used in therapeutic monitoring and drug discovery. Also, some changes take place in the fluorescence properties of labeled analytes. 

  • Enzyme Immunoassay 

The enzyme immunoassay test was developed mainly to detect the presence of the antigen by using antibodies. While, there are various types of EIAs that consist of the antibody molecule whose main function is to bind an enzyme. Moreover, the EIA is used mainly for immunostaining and the types of enzyme immunoassays are homogeneous immunoassay and heterogeneous immunoassays. The homogeneous method is generally carried away for minor analytes such as drugs.

Such assays are referred to as enzyme multiplied immunoassay techniques. The antibody is immobilized in case of a heterogeneous competitive immunometric assay. Also, in the heterogeneous immunoassay, an analyte has a combination of antigens that work for the common binding site. 

  • Chemiluminescence Immunoassay (CLIA)

CLIA is concerned with producing light by way of emitting electromagnetic radiation that is caused by chemical reactions. This assay combines the immunochemical reactions along with the chemiluminescence technique just like other immunoassays (ELISA, FIA, and RIA).

We can say undoubtedly, that CLIA has gained popularity in recent years among different fields including food safety and pharmaceutical analysis, life science, environmental monitoring, and clinical diagnosis. There are mainly three types of label systems under CLIA including:

  • Label Chemical Directly involved in the light emission reaction
  • Redox Reaction Mediated Light Emission Reaction
  • Enzyme-Catalyzed Light Emission Reaction


Liposome Immunoassay 

This immunoassay method of testing is relatively a simple procedure to qualitatively and quantitatively examine the absence or presence of the antigenic materials or the antibodies for the diagnostic process. Liposomes were mainly prepared from the phospholipids and cholesterol including MBPE with thiol-containing antigens for conjunction.

The LIAs basic principles consist of heterogeneous, homogeneous, direct and competitive techniques. LIAs are mainly performed by Liposomes.


Immunoassay tests could help in identifying different compounds like biomarkers that indicate prognosis or disease diagnosis, low molecular weight drugs, and macromolecular biomolecules.The immunosensors are also improved continually leading to performance improvements such as automation of the methods, increasing the sensitivity, simplification of the assay procedure, decreasing the analysis time, and miniaturization of the analytical equipment.