Recombinant Anti-PD1 antibody [CAL20] (ab237728)

Fluorescence multiplex immunohistochemical analysis of normal human tonsil tissue (formalin-fixed paraffin-embedded section).

Merged staining of anti-PD1 (ab237728; orange; Opal™520), anti-PDL1 (ab237726; green; Opal™540), anti-CD68 (ab192847; yellow; Opal™570), anti-CD3 (ab16669; red; Opal™620), anti-Ki67 (ab16667; light blue; Opal™650) and anti-PanCK (ab7753; grey; Opal™690).

The immunostaining was performed on a Leica Biosystems BOND® RX instrument with an Opal™ 7-color automation IHC kit (NEL821001KT, Akoya Biosciences®).

The section was incubated in six rounds of staining; in the order of ab237728 (1/500 dilution), ab237726 (1/500 dilution), ab192847 (1/300 dilution), ab16669 (1/300 dilution), ab16667 (1/200 dilution) and ab7753 (1/200 dilution); each using a separate fluorescent tyramide signal amplification system.

Sodium citrate antigen retrieval (Leica ER1, pH6.0, 30 minutes) was used in between rounds of tyramide signal amplification to remove the antibody from the previous round, to avoid any cross-reactivity.

DAPI (dark blue) was used as a nuclear counter stain.

Microscopy and pseudocoloring of individual Opal™ dyes was performed using a Vectra Polaris.

Immunohistochemical analysis of paraffin-embeded human tonsil tissue labeling PD1 with ab237728 at 1/500 dilution, followed by Goat Anti-Rabbit IgG H&L (HRP) ready to use. Positive staining on the human tonsil.is observed. Counter stained with hematoxylin.

Secondary antibody only control: Used PBS instead of primary antibody, secondary antibody is Goat Anti-Rabbit IgG H&L (HRP) ready to use.

Heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0) for 30 mins.

The section was incubated with ab237728 for 15 mins at room temperature.

The immunostaining was performed on a Leica Biosystems BOND^® RX instrument.

Immunofluorescent analysis of 4% paraformaldehyde-fixed, 0.1% Triton X-100 permeabilized MOLT-4 (human lymphoblastic leukemia cell line) cells labeling PD1 with ab237728 at 1/50 dilution, followed by Goat Anti-Rabbit IgG H&L (Alexa Fluor^® 488) (ab150077) secondary antibody at 1/1000 dilution (green). Confocal image showing membranous staining in MOLT-4 cells treated with PMA (10ng/ml 24h) and Ionomycin(500ng/ml 24h). The nuclear counter stain is DAPI (blue). Tubulin is detected with Anti-alpha Tubulin antibody [DM1A] - Microtubule Marker (Alexa Fluor^® 594) (ab195889) at 1/200 dilution (red).

Secondary antibody only control: Used PBS instead of primary antibody, followed by Goat Anti-Rabbit IgG H&L (Alexa Fluor^® 488) (ab150077) secondary antibody at 1/1000 dilution.

Cells were either untreated, ot treated with treated with PMA (10ng/ml 24h) and Ionomycin (500ng/ml 24h).

Blocking and dilution buffer: 5% NFDM/TBST.

Formalin-fixed, paraffin-embedded human lymph node tissue stained for PD1 using ab237728 at 0.125 µg/ml dilution in immunohistochemical analysis.

Formalin-fixed, paraffin-embedded human lung carcinoma tissue stained for PD1 using ab237728 at 0.125 µg/ml dilution in immunohistochemical analysis.