PCR is used to diagnose multiple infections, such as: - COVID-19: SARS-CoV-2 detection has become one of the most common uses of PCR. - Influenza: Differentiating between influenza types A and B. - HIV: Quantifying viral load in HIV-infected individuals. - Tuberculosis: Detecting Mycobacterium tuberculosis in clinical samples. - Sexually Transmitted Infections (STIs): Identifying pathogens like Chlamydia trachomatis and Neisseria gonorrhoeae.