Basic Immunohistochemistry (IHC) 1 CIHRT Exhibit P-1603 Page - PowerPoint PPT Presentation

CIHRT Exhibit P-1603 Page 1 Basic Immunohistochemistry (IHC) 1

CIHRT Exhibit P-1603 Page 2 Basic IHC � IHC harnesses the immunological mechanism in human beings, eg. cold virus. � Lymphoid cells produce antibodies to fight viruses. � These antibodies are biologically manufactured by our cells to target the virus. 2

CIHRT Exhibit P-1603 Page 3 Basic IHC � IHC antibodies for pathology diagnosis apply the same principle. Antibody makers extract the protein from human cells and inject them into mice/rabbits. 3

CIHRT Exhibit P-1603 Page 4 Basic IHC � After a period of time, mice/rabbits produce the specific antibodies against the human cell proteins. 4

CIHRT Exhibit P-1603 Page 5 Basic IHC � There are different and specific protein targets that the antibodies locate, eg. Estrogen and Progesterone Receptor protein. This is the antigen. 5

CIHRT Exhibit P-1603 Page 6 Basic IHC � Once the antibodies and antigen react, they need to be examined under a microscope. 6

CIHRT Exhibit P-1603 Page 7 Basic IHC � For microscopic analysis, the tissue removed from the patient is preserved in formalin and placed on paraffin wax blocks. These blocks are cut into thin slices or sections and placed on glass slides. 7

CIHRT Exhibit P-1603 Page 8 Basic IHC � Then the tissue is put through a complex laboratory procedure of antigen retrieval (AR) because formalin fixation masks the antigens. AR increases the accessibility to the antigen. 8

CIHRT Exhibit P-1603 Page 9 Basic IHC � Following completion of the AR, the next step is the antibody reaction. 9

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CIHRT Exhibit P-1603 Page 12 Basic IHC � After the antibody reaction, comes the final stage of the technical process - the detection system. 12

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CIHRT Exhibit P-1603 Page 14 Basic IHC DAB=diaminobenzidine 14

CIHRT Exhibit P-1603 Page 15 Basic IHC � Finally, the slides are analyzed by a pathologist who interprets the immunostaining of the cells and cell structure. Examples: 1) nuclear 2) cytoplasmic 3) membranous 15

CIHRT Exhibit P-1603 Page 16 Basic IHC • IHC is a multi-varied tool for prognostic and diagnostic purposes. This includes 1) differentiation of tumors, 2) classification of lymphomas (eg. CD20 for B cell lymphomas) 3) to identify invasion of cancerous cells and 4) to identify diagnostic and prognostic proteins in the tissue (eg. (ER/PR). 16