Following statements are related to slow block to polyspermy in mammals.

A. A First slow block to polyspermy comes When the cortical granules fuse with the egg cell membrane, they release protein-digesting enzymes which is called as ovastacin that modify the zona pellucida proteins.

B. A second slow block to polyspermy comes from the so-called zinc spark, the release of billions of zinc ions that is induced by the entry of the first sperm, these released zinc ions are seen to bind to the egg cell membrane form a “zinc shield” that prevents further sperm entry.

C. A third slow block to polyspermy occurs at the level of the egg cell membrane and involves Juno.

Which of the following is incorrect?

TLS Online TPP Program

#Question id: 18775

#Unit 13. Methods in Biology

which of the following technique is a highly sensitive and quantitative procedure that utilizes radioactively labelled antigen or antibody

TLS Online TPP Program

#Question id: 18776

#Unit 13. Methods in Biology

In Western blotting, a protein mixture is separated by electrophoresis; then the protein bands are electrophoretically transferred onto nitrocellulose and identified with 

TLS Online TPP Program

#Question id: 18777

#Unit 13. Methods in Biology

which of the following technique using antibodies labelled with fluorescent molecules can be used to visualize antigen on or within cells.

TLS Online TPP Program

#Question id: 18778

#Unit 13. Methods in Biology

which of the following technique provides an unusually powerful technology for the quantitative analysis and sorting of cell populations labelled with one or more fluorescent antibodies.

TLS Online TPP Program

#Question id: 18779

#Unit 13. Methods in Biology

Flow-cytometric analysis for the detection and measurement of subpopulations of leukocytes, including those of leukaemia, is usually performed using monoclonal antibodies. Why is this the case?

Choose whether each of the following statements is true 

a) Indirect immunofluorescence is a more sensitive technique than direct immunofluorescence

b) Most antigens induce a polyclonal response. 

c) For precipitation to occur, both antigen and antibody must be multivalent.

d) ELISA tests using chemiluminescence are more sensitive than chromogenic ones and precipitation tests are more sensitive than agglutination tests

TLS Online TPP Program

#Question id: 18780

#Unit 13. Methods in Biology

Which of the following does not participate in the formation of antigen-antibody complexes?