Immunofluorescence - Oct4 antibody - Embryonic Stem Cell Marker (ab19857)

The image shows a colony of differentiating Human Embryonic Stem Cells double-stained with anti-Oct4 antibody ab19857 (green) and Sox17 antibody (red). The nuclei of Oct4-positive undifferentiated hESCs stained bright green. Staining was restricted to the nuclei. Oct4-positive nuclei were Sox17-negative, and vice versa. This antibody can be used as a marker of Oct4-positive undifferentiated Human Embryonic Stem Cells.

Ludovic Vallier, University of Cambridge

Western blot

All lanes : Anti-Oct4 antibody - ChIP Grade (ab19857) at 1 µg/ml

Lane 1 : MEL-1 (Human embryonic stem cell, male cell line) Whole Cell Lysate (ab27198)
Lane 2 : MEL-2 (Human embryonic stem cell, female cell line) Whole Cell Lysate (ab27196)
Lane 3 : IOUD2 (Mouse embryonic stem cell, selected for Oct4 expression cell line) Whole Cell Lysate (ab27202)
Lane 4 : F9 (Mouse embryonic carcinoma cell line) Whole Cell Lysate (ab27193)
Lane 5 : MEL-1 (Human embryonic stem cell, male cell line) Whole Cell Lysate (ab27198) with Oct4 peptide (ab20650) at 1 µg/ml
Lane 6 : MEL-2 (Human embryonic stem cell, female cell line) Whole Cell Lysate (ab27196) with Oct4 peptide (ab20650) at 1 µg/ml
Lane 7 : IOUD2 (Mouse embryonic stem cell, selected for Oct4 expression cell line) Whole Cell Lysate (ab27202) with Oct4 peptide (ab20650) at 1 µg/ml
Lane 8 : F9 (Mouse embryonic carcinoma cell line) Whole Cell Lysate (ab27193) with Oct4 peptide (ab20650) at 1 µg/ml

Lysates/proteins at 10 µl per lane.


Observed band size : 48 kDa (why is the actual band size different from the predicted?)
Additional bands at : 65 kDa. We are unsure as to the identity of these extra bands.

MEL-1 and MEL-2 Human Embryonic Stem Cell Lysates (ab27198 and ab27196), IOUD2 Oct4-expressing Mouse Embryonic Stem Cell Lysate (ab272020) and F9 Mouse Embryonic Carcinoma Cell Lysate (ab27193) all contain Oct4 protein. As expected, a band corresponding to Oct4 was detected in all four of the lysates by Westen Blot using anti-Oct4 antibody ab19857. Each of the Oct4 bands was specifically blocked using the immunising peptide of ab19857. The origin of the additional 65 kDa band detected in Lane 3 is unknown and may be a non-specific band that is recognised, in addition to Oct4, by ab19857 in mouse embryonic stem cells.

Immunocytochemistry/ Immunofluorescence - Oct4 antibody - Embryonic Stem Cell Marker (ab19857)

ICC/IF image of ab19857 stained mouse embryonic stem cells. The cells were 4% formalin fixed (10 min) and then incubated in 1%BSA / 10% normal goat serum / 0.3M glycine in 0.1% PBS-Tween for 1h to permeabilise the cells and block non-specific protein-protein interactions. The cells were then incubated with the antibody (ab19857, 1µg/ml) overnight at +4ºC. The secondary antibody (green) was Alexa Fluor® 488 goat anti-rabbit IgG (H+L) used at a 1/1000 dilution for 1h. Alexa Fluor® 594 WGA was used to label plasma membranes (red) at a 1/200 dilution for 1h. DAPI was used to stain the cell nuclei (blue).

Immunocytochemistry/ Immunofluorescence - Oct4 antibody - Embryonic Stem Cell Marker (ab19857)

ICC/IF image of ab19857 stained Mouse Embryonic Stem cells. The cells were PFA fixed (4% PFA, 20 min) and incubated with the antibody (ab19857, 1µg/ml) for 1h at room temperature. The secondary antibody (green) was Alexa Fluor® 488 goat anti-rabbit IgG (H+L) used at a 1/1000 dilution for 1h. Image-iT^TM FX Signal Enhancer was used as the primary blocking agent, 5% BSA (in TBS-T) was used for all other blocking steps. DAPI was used to stain the cell nuclei (blue).

The large nuclei of the Feeder cells can be seen in the image; ab19857 does not localise to these nuclei. ab19857 can be seen localising to the much smaller nuclei of the Mouse Embryonic Stem cells.

Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Oct4 antibody - Embryonic Stem Cell Marker (ab19857)

Mouse E6 - E6.5 embryos were sectioned and then fixed in paraformaldehyde. Antigen retrieval was performed using citric acid and the sections permeablized and blocked for 1 hour in serum. Embryos were stained with ab19857 (1/2500) in 10% serum, 1% ovalbumin in PBSTween for 14 hours at 4C. They were then washed and stained with a goat anti-rabbit biotin conjugated antibody (1/2000) and developed using ABC and then DAB for color. Staining is within the epiblast as expected.

Flow Cytometry - Anti-Oct4 antibody - ChIP Grade (ab19857)

Overlay histogram of Oct4 staining in mouse embryonic stem cells using ab19857 at 1:100 dilution. Purple histogram represents negative control (rabbit IgG); green line represents anti-Oct4 antibody (ab19857).

This image is taken from an abreview by Kate Hawkins

Western blot

All lanes : Anti-Oct4 antibody - ChIP Grade (ab19857) at 1 µg/ml

Lane 1 : Human embryonic stem cell lysate
Lane 2 : Mouse embryonic stem cell lysate
Lane 3 : Mouse embryonic germ cell lysate
Lane 4 : Human embryonic stem cell lysate with Oct4 peptide (ab20650) at 1 µg/ml
Lane 5 : Mouse embryonic stem cell lysate with Oct4 peptide (ab20650) at 1 µg/ml
Lane 6 : Mouse embryonic germ cell lysate with Oct4 peptide (ab20650) at 1 µg/ml

Lysates/proteins at 20 µg per lane.


Predicted band size : 39 kDa
Observed band size : 43 kDa (why is the actual band size different from the predicted?)
Additional bands at : 55 kDa (possible glycosylated form,cross reactivity).

Anti-Oct4 antibody ab19857 only detected a band corresponding to the expected size of Oct4 in human ES cell lysate. In mouse ES and EG cell lysates, ab19857 detected a band of approximately 55 kDa in addition to the expected 39 kDa Oct4 band.