1. A CALL TO ARMS

3. In the 1880s German doctor, Robert Koch, developed a series of methods for identifying which organism was the cause of a particular disease. These postulates are still in use today.
This led the way for specific treatment for many disease- causing pathogens.
KOCH’S POSTULATES

4. Response of Immune System to Disease-Causing Organisms
A. RECOGNITION: white blood cell surrounds pathogen and signals killer T cells (not shown); more T cells
are produced; helper T cells signal B cells
B. MOBILIZATION: B cells produce antibodies
C. DISPOSAL: antibodies destroy pathogens
D. IMMUNITY: some antibodies remain for future use (memory B cells)

5. Antigen-Antibody Complex
Antibodies all have the same basic Y structure
Antibodies have different antigen binding sites designed to fit the shape
of specific antigens
Antibodies bind to antigens like a lock and key to form the Antigen-Antibody Complex

6. INDIRECT ELISA (enzyme – linked immunoabsorbant assay)
Used to detect infection by testing patients’ blood serum for the presence
or absence of antibodies against a particular pathogen
Presence of antibodies indicates the individual has been infected and that
their body has launched an immune response against the disease-causing agent
Test for: HIV, Avian Flu, West Nile, Lyme Disease, Smallpox, SARS, Syphilis,
Rocky Mountain Spotted Fever

7. Human Immunodeficiency
Virus
Virus responsible for causing
Acquired
Immune Deficiency Syndrome or
AIDS

8. Rates of Persons Aged 18–64 Years Living with a Diagnosis of HIV Infection, Year-End 2008—United States

9. LYME DISEASE Vector = deer tick
Reported Cases in the United States, 2012

10. Avian Influenza (Bird Flu)

12. ELISA TEST RESULTS
ELISA data from three patients. Numbers are expressed as optical density at 450 nm. The cutoff value indicating a positive result is Optical densities of to are indeterminate and need to be retested. Values below are considered to be negative. In most cases, a patient will be retested if the serum gives a positive result. If the ELISA retests are positive, the patient will then be retested by western blotting analysis.
Positive Control
Negative Control
Patient A
Patient B
Patient C
Assay Control
1.689
0.153
O.055
0.412
1.999
0.123

13. ELISA SIMULATION RESULTS
In this simulated ELISA, all reaction wells will turn light green when the chromogen
substrate is added. A change in color from light green to purple indicates a positive result.