Question

question 4 (1 point) saved

1. the ouchterlony double - diffusion test can help identify unknown antigen or antibody using precipitation in

a) liquid media in test tubes.
b) droplets on glass slides.
c) agar wells in petri plates.
d) electrophoresis gel

question 5 (1 point) saved

1. the elisa test

a) uses enzymes and dyes.
b) uses radioisotopes.
c) uses an electric current.
d) involves subcutaneous injection of antigen to elicit a response.

Explanation:

Question 4

The Ouchterlony double - diffusion test is performed in agar wells within Petri plates. In this test, antigen and antibody diffuse through the agar gel, and precipitation lines form where they meet at optimal proportions. Liquid media in test tubes (option a) is not the correct medium for this test. Droplets on glass slides (option b) do not provide the right diffusion environment. Electrophoresis gel (option d) is used for electrophoresis - based techniques, not for Ouchterlony double - diffusion.

The ELISA (Enzyme - Linked Immunosorbent Assay) test uses enzymes (which are linked to antibodies or antigens) and dyes (or substrates that produce a colored reaction when acted upon by the enzyme). Radioisotopes are used in radioimmunoassays, not ELISA (so option b is wrong). An electric current is used in electrophoresis, not ELISA (option c is wrong). Subcutaneous injection of antigen to elicit a response is related to immunization or skin tests, not ELISA (option d is wrong).

Answer:

c) agar wells in Petri plates.

Question 5