Update app.py

app.py

@@ -127,9 +127,9 @@ col1, col2, col3, col4 = st.columns([1, 1, 1, 1])
 with col1:
     st.button("Demo: immunology", on_click=demo_immunology_callback)
 with col2:
-    st.button("Demo: virology", on_click=demo_virology_callback)
-with col3:
     st.button("Demo: microbiology", on_click=demo_microbiology_callback)
+with col3:
+    st.button("Demo: virology", on_click=demo_virology_callback)
 with col4:
     st.button("Clear fields", on_click=clear_callback)