1. Human insulin.

2. Vaccines .

Steps of ELISA

1. A micro titer plate is coated with antigen.

2. Primary antibody specific to antigen for diagnosis  is added to the plate. The antibody interacts with the antigen. then the plate is washed to remove any extra free antibody.

3. Secondary antibody which has a tag  is then added  to the well. The secondary antibody attaches to the primary antibody. The plate  is washed to remove free secondary antibody.

4.Chromagen is added which produces color and aids in detection.

(1) Their genes are altered by manipulation.

(2) They have incresed resistance to pests and can tolerate abiotic stresses more efficiently.

(3) They have high nutritional value.

(4) They may produce biological products which help in curing diseases.

(i) Therapeutics (ii) Genetically modified crops

(iii) Molecular diagnostics (iv) Processed food items.

(v) Bioremediation (vi) Gene therapy.

(vii) Vaccine production.

2. Cloned gene can be used to detect antibodies or antigens in infections. Like in ELISA which is based on antibody-antigen interaction.