Patent ID: 11899016
Assignee: VENTANA MEDICAL SYSTEMS, INC.
Field: Measurement (Instruments)
Classification: CPC G  A  C | IPC C  G

Claim 12:
13. An immunohistochemical method of identifying PD-L1 positive immune cells in a tumor tissue section, said method comprising:
contacting a tissue sample with a first primary antibody specific to PD-L1 protein in a manner to effect binding of the first primary antibody to the tissue sample in proximity to PD-L1 protein expressed by the tissue sample;
depositing a first enzyme in proximity to the first primary antibody bound to the tissue sample;
reacting the first enzyme with a first substrate to effect deposition of 4-(dimethylamino) azobenzene-4′-sulfonamide on the tissue sample in proximity to the first primary antibody, wherein the 4-(dimethylamino) azobenzene-4′-sulfonamide is deposited via a signaling conjugate comprising tyramide directly conjugated to 4-(dimethylamino) azobenzene-4′-sulfonamide;
contacting the tissue sample with a second primary antibody specific to at least one immune cell marker protein in a manner to effect binding of the second primary antibody to the tissue sample in proximity to immune cell marker protein expressed by the tissue sample;
depositing a second enzyme in proximity to the second primary antibody bound to the tissue sample; and
reacting the second enzyme with a second substrate to effect deposition of tetramethylrhodamine on the tissue sample in proximity to the second primary antibody, wherein the tetramethylrhodamine is deposited via a signaling conjugate comprising tyramide directly conjugated to the tetramethylrhodamine, and
detecting by brightfield microscopy cells that are co-stained with tetramethylrhodamine and 4-(dimethylamino) azobenzene-4′-sulfonamide in the tissue sample, thereby identifying PD-L1 positive immune cells.