The Enzyme-Linked Immunosorbent Assay (ELISA) is a widely used biochemical test for detecting and measuring antibodies, antigens, proteins, and hormones in biological samples. It plays a crucial role in medical diagnostics, research, and disease detection.

📌 How Does ELISA Work?

✅ Relies on antibody-antigen interactions to detect the presence of specific molecules.
✅ Uses enzymes to produce a measurable signal indicating a positive or negative result.
✅ Highly sensitive and precise for quantifying biomolecules in blood or other fluids.

Types of ELISA:

🔹 Direct ELISA – Detects an antigen using a single antibody.
🔹 Indirect ELISA – Uses a primary and secondary antibody for enhanced sensitivity.
🔹 Sandwich ELISA – Captures an antigen between two antibodies for high specificity.
🔹 Competitive ELISA – Measures antigen levels by detecting competition between bound and free antigens.

Applications: What Can ELISA Detect?

Infectious diseases (HIV, Syphilis, Zika, Lyme disease, Rotavirus)
Autoimmune disorders (Pernicious anemia)
Hormone levels & biomarkers
Toxin & allergen detection

✅ Advantages:

✔️ High sensitivity & specificity
✔️ Cost-effective & easy to perform
✔️ Widely used in diagnostics & research

⚠️ Limitations:

❌ Complex sample preparation
❌ Limited to known targets
❌ Not ideal for very small molecules

💡 ELISA is revolutionizing medical diagnostics and research!