1. The first step in the production of a vaccine would be the generation of the antigen that will trigger the respective immune response in the body – in this case that antigen would be the poliovirus. This is accomplished by infecting and growing these viruses on the given monkey kidney cells. During this step, it is crucial to check for any possible cell cross contamination (by HeLa cells) that might have occurred during the procedure. This is because we want to ensure that the virus is being obtained from the correct cell line. In order to check for cell cross contamination, methods such as karyotyping and isoenzyme analysis can be performed on the growing cells to ensure that the cells are indeed the monkey kidney cells.2. The purpose of this second step would be to continuously grow these virally infected cells in order to meet the sufficient amounts for use on an industrial scale. Where these viruses have to be grown to a very large amount to accommodate the large number of vaccines required. During this step, we can monitor the growth of the virally infected cells through the use of Fluorescence Activated Cell Sorter (FACS). This can be done through the use of Propidium Iodide (PI) fluorophores, which are only able to detect dead cells as they are unable to permeate through live cells, on the growing cells. The results from the FACS data for PI would help us determine the relative amounts of live and dead cells – as virally infected cells would eventually burst and die when the virus is being released from the cell. When the desired amount of viruses is obtained, we can then proceed to step 3.3. In the third step, purification of these viruses must be done. This is accomplished through purification methods such as ultracentrifugation and chromatography techniques.4. For the fourth step, it would be making modifications and additional changes to these purified polioviruses. As we know, the poliovirus is extremely contagious and dead – which means that further steps have to be taken to address this issue when it comes to using these viruses for vaccines. In order to prevent possible complications and safety hazards in this vaccine, the poliovirus is usually inactivated through heat and chemical processes. Inactivated vaccines are more stable and safer as compared to live vaccines. To check if the poliovirus is indeed inactivated, we can perform Clonogenic or MTT assays on uninfected healthy cells. If a Clonogenic assay is performed, the regenerative potential of the healthy cells should remain unaffected if the poliovirus has been successfully inactivated. If a MTT assay is performed, there should be no indication of dead cells if the poliovirus has been successfully inactivated. After successful inactivation of the poliovirus, we can proceed to step 5.5. In the fifth step, additional components are added along with the inactivated poliovirus. Such components may include the addition of an adjuvant, a material capable of inducing a stronger immune response in patients towards the poliovirus. Stabilizers and preservatives, used to prolong the storage life of this vaccine, are also added. All of these components would be combined together to constitute the final vaccine. In order to determine the appropriate dosage of vaccine, a microtitration assay of the vaccine should be performed. By performing this assay, we can observe how the varying dosages of the vaccine would affect protein synthesis of healthy cells which then allows us to determine the appropriate dosage required. 6. In the sixth and final step, the poliovirus vaccine would then be packed into vials or syringes for storage. Now, this vaccine would be sent for clinical trials where if successful, will be sent for approval by authorities. If this vaccine meets all the safety requirements, the vaccine can then be distributed worldwide. During the clinical trials, the vaccines would continuously be tested for their safety and whether they generate any possible side effects on patients.