Antigen and Antibody immunoassays -2

Question 1

Direct ELISA ( sandwich ELISA)

Answer 1

used to detect or quantitate an antigen

Question 2

Indirect ELISA

Answer 2

used to detect or quantitate antibody

Question 3

fluorochromes

Answer 3

are chemical substances that are capable of absorbing a short wavelength and instantaneously emitting a longer wavelength light

Question 4

Fluroescein isothiocyanate (FITC) absorbs ___ and emits and intense _____ fluorescence.

Answer 4

• blue light

- yellow-green

Question 5

Rhodamine absorbs in the _____ range and emits a deep___ fluorescence

Answer 5

• yellow-green

- red

Question 6

Direct fluorescent antibody test

Answer 6

is used to detect the presence of antigen

Question 7

indirect fluorescent antibody test

Answer 7

used for the detection and quantitation of antibodies

Question 8

lattice

Answer 8

the interaction between an antibody and a soluble antigen in aqueous solution forms this

Question 9

prozone

Answer 9

uncombined antibody is present in the supernatant. due to the presence of excess antibody, each antigen molecule is covered with antibody , preventing cross-linkage and thus precipitation

Question 10

equivalence zone

Answer 10

both antigen and antibody are completely precipitated and no uncombined Ag or Ab is present in the supernatant

Question 11

zone of antigen excess

Answer 11

uncombined Ag is present in the supernatant

Question 12

coogins test

Answer 12

detects presence of Abs against equine infectious anemia virus in horses

Question 13

identity

Answer 13

occurs when two Ags share identical epitopes

Question 14

nonidentity

Answer 14

occurs when two antigens are unrelated

Question 15

partial identity

Answer 15

occurs when two Ags share common epitopes but one or the other also has unique epitopes.

Question 16

neutralization test

Answer 16

are used to estimate the ability of antibody to neutralize the biological activity of viable viruses in vitro

Question 17

virus neutralization test

Answer 17

these are widely employed in the quantitation of antiviral antibodies or virus identification

Question 18

A negative result of titration of complement is shown by:

Answer 18

lysis of sensitized RBCs

Question 19

A positive result of titration of complement is shown by:

Answer 19

absence of lysis