DDX1 / ATP-dependent RNA helicase DDX1 · IHC design guide

Design Immunohistochemistry for DDX1

Plan DDX1 paraffin-section IHC around widespread nuclear staining (HPA tissue IHC). This guide covers fixation consistency, primary antibody titration at 0.5–1 µg/mL (datasheet A03727-1), DAB detection (datasheet A03727-1) and nuclear scoring.

Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use

Immunohistochemistry protocol sheet for DDX1 (IHC for DDX1): expected localisation Nuclear staining (HPA tissue IHC); cytosolic localization possible (UniProt), antibody A03727-1, validated IHC image, and IHC protocol steps — Printable **DDX1** IHC protocol sheet — expected localisation Nuclear staining (HPA tissue IHC); cytosolic localization possible (UniProt), antibody A03727-1, controls and protocol steps. Open the full DDX1 IHC guide →

Navigate to: Protocols Staining pattern Controls Antibodies

DDX1 Immunohistochemistry Experimental Design Guide

Expected localisation, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.

Must know before staining

	Expected localisation	Nuclear staining (HPA tissue IHC); cytosolic localization possible (UniProt)
	Staining pattern	Widespread nuclear staining across tissue cell types (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A03727-1)
	Positive control ⓘ	Appendix+4 more · see all
	Negative control ⓘ	None in HPA (detected in all 44 tissues); use no-primary + isotype controls

Important caveats

Reasons your staining may differ from the expected pattern.

	Fixation	Keep fixation consistent across sections (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A03727-1)
	Caveat	Active transcription can shift DDX1 into nuclei (UniProt)
	Regulation	Higher transcription in neuroectodermal tissues (UniProt)
	Isoform / epitope	3 isoforms; antibody epitope coverage is unspecified (UniProt)

Section 1

Recommended DDX1 IHC & IF Protocols

The catalog antibody protocol uses EDTA pH 8.0 heat retrieval (datasheet: A03727-1); the published IHC protocols below cover hepatocellular carcinoma and colorectal cancer specimens (PMC10921000; PMC6113447).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded rat testis tissue; fixative not specified (datasheet A03727-1)
Fixation	Image fixative and duration unreported (datasheet A03727-1); verify before use.
Sectioning	4–5 µm sections on charged slides (standard)
Deparaffinisation	Xylene, graded ethanol series to water (standard)
Antigen retrieval	Heat retrieval: EDTA pH 8.0 (datasheet A03727-1); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A03727-1)
Primary antibody	Rabbit anti-DDX1, 0.5-1μg/ml (datasheet A03727-1)
Primary incubation	Overnight at 4 °C (datasheet A03727-1)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A03727-1)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	DDX1-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: Ubiquitous nuclear expression. No signal in the no-primary control.

💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet: A03727-1); the published excerpts do not specify retrieval conditions (PMC10921000; PMC6113447).

Section 2

What Is the Expected DDX1 Staining Pattern?

In paraffin-section IHC, expect DDX1 staining mainly in nuclei across many cell types, including appendix glandular cells and bone-marrow hematopoietic cells (HPA: ubiquitous nuclear expression; High in both cell types). HPA rates the tissue pattern Enhanced, with medium consistency between staining and RNA data (HPA: tissue IHC). DDX1 has no transmembrane segment, so a membrane pattern is unexpected (UniProt Q92499 topology).

What am I looking at on my slide?
Clear nuclear staining in appendix glandular cells or bone-marrow hematopoietic cells.	This fits the expected compartment and two reported High-staining cell groups (HPA: ubiquitous nuclear expression; High in appendix glandular and bone-marrow hematopoietic cells). Compare staining within the identified cells; a dark section alone cannot establish the cellular pattern (general IHC practice).
Predominantly membranous staining, or cytoplasmic staining with little nuclear signal.	Reassess the result: HPA reports ubiquitous nuclear tissue staining, while UniProt reports no transmembrane segment (HPA: tissue IHC; UniProt Q92499 topology). Cytosolic DDX1 is also documented, so cytoplasmic signal alone is not proof of an artefact (HPA: ICC-IF supported cytosol).
Strong signal in an unexpected cell population, with weak signal in the identified HPA High cells.	Check cell identification, antibody specificity and chromogenic background before assigning the signal to DDX1 (general IHC practice). HPA reports High staining in specified cell groups but calls the overall nuclear pattern ubiquitous; its examples do not establish negative cell types (HPA: tissue IHC).
Diffuse brown haze across cells, extracellular spaces or the whole section.	A haze that obscures nuclear boundaries cannot be scored as the reported nuclear pattern (HPA: ubiquitous nuclear expression; general IHC practice). Check the no-primary control, blocking, washes and detection background; endogenous chromogenic activity is a possible technical cause (general IHC practice).
No nuclear signal in a section containing a reported High-staining cell group.	Treat this as an unresolved assay result before calling DDX1 absent (HPA: High in the listed cell groups; general IHC practice). Confirm that the relevant cells are present, then review the antibody's IHC validation, retrieval and detection controls (general IHC practice).

💡Expected DDX1 appearanceA convincing positive shows discernible nuclear chromogen in identified cells, with potentially High staining in HPA-listed cell groups; isolated membrane outlines or diffuse haze do not reproduce that pattern (HPA: ubiquitous nuclear expression; High in listed groups; UniProt Q92499 topology; general IHC practice).

How each factor affects the staining
Cell population and tissue context	HPA reports ubiquitous nuclear expression and High staining in several identified populations, including caudate neuronal cells and cerebral-cortex glial cells (HPA: tissue IHC). These examples guide cell-level review; they do not define a negative tissue (HPA: no negative tissue listed).
Antibody validation	HPA034502 and HPA034503 have Enhanced IHC status; CAB012280 has Supported IHC status (HPA: antibody validation). These ratings describe those antibodies, so do not transfer them to an unidentified catalog antibody (HPA: antibody validation; general IHC practice).
IF/ICC question: can cytosolic signal be expected?	Yes. HPA reports mainly nucleoplasmic localization with additional supported cytosolic localization in ICC-IF (HPA: subcellular ICC-IF). That observation helps interpret IF/ICC images; it does not establish a separate paraffin-IHC staining threshold (HPA: tissue IHC; general IHC practice).
Isoform recognition and induced foci	UniProt lists 3 DDX1 isoforms and reports relocalization to foci after irradiation and to stress granules under stress (UniProt Q92499). Without an antibody epitope or treatment history, neither isoform coverage nor a punctate routine-IHC pattern can be predicted (general IHC practice).

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Reported High-staining cells show no nuclear signal.	The assay may have failed, or the relevant cells may be absent from the examined area (general IHC practice).	Locate the identified cell group first; then check an IHC-validated antibody, the documented retrieval conditions and detection controls (HPA: High in listed cell groups; general IHC practice).
Most visible signal outlines cell membranes.	That distribution conflicts with the reported nuclear tissue pattern and lacks support from DDX1 topology (HPA: tissue IHC; UniProt Q92499 topology).	Review morphology and a no-primary control, then reassess antibody-specific signal and detection background (general IHC practice).
Unexpected cells stain strongly while HPA-listed cells stain weakly.	Cell misidentification, cross-reactivity or detection background may explain the discrepancy (general IHC practice). HPA lists no negative tissues (HPA: tissue IHC).	Identify cell types on the counterstained section and compare an appropriate antibody or control before interpreting the difference (general IHC practice).
Brown staining is widespread and nuclear edges are hard to distinguish.	Nonspecific reagent signal or endogenous chromogenic activity may obscure the pattern (general IHC practice).	Inspect a no-primary control; review blocking, washes and endogenous-activity controls appropriate to the detection system (general IHC practice).
Cytoplasmic signal accompanies clear nuclear staining.	DDX1 can also occur in cytosol, although HPA describes tissue IHC as ubiquitously nuclear (HPA: supported cytosol in ICC-IF; HPA: tissue IHC).	Score the nuclear component separately and check whether cytoplasmic staining is cell-associated and above control background (general IHC practice).
Punctate staining appears after a documented stress or irradiation treatment.	UniProt reports stress granules and irradiation-induced DDX1 foci (UniProt Q92499); the treatment alone does not identify every punctum.	Record the treatment and compartment, compare matched controls, and require corroboration before assigning puncta to DDX1 structures (general IHC practice).

Source: UniProt Q92499 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing DDX1 staining

IHC analysis of DDX1 using anti-DDX1 antibody (A03727-1). DDX1 was detected in paraffin-embedded section of rat testis tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1μg/ml rabbit anti-DDX1 Antibody (A03727-1) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A03727-1 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (A03727-1). DDX1 was detected in paraffin-embedded section of rat testis tissue. Heat mediated

IHC analysis of DDX1 using anti-DDX1 antibody (A03727-1). DDX1 was detected in paraffin-embedded section of mouse testis tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1μg/ml rabbit anti-DDX1 Antibody (A03727-1) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A03727-1 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (A03727-1). DDX1 was detected in paraffin-embedded section of mouse testis tissue. Heat mediat

IF analysis of DDX1 using anti-DDX1 antibody (A03727-1). DDX1 was detected in immunocytochemical section of U20S cells. Enzyme antigen retrieval was performed using IHC enzyme antigen retrieval reagent (AR0022) for 15 mins. The cells were blocked with 10% goat serum. And then incubated with 2μg/mL rabbit anti-DDX1 Antibody (A03727-1) overnight at 4°C. DyLight®488 Conjugated Goat Anti-Rabbit IgG (BA1127) was used as secondary antibody at 1:100 dilution and incubated for 30 minutes at 37°C. The section was counterstained with DAPI. Visualize using a fluorescence microscope and filter sets appropriate for the label used.

A03727-1 · IFIF analysis of DDX1 using anti-DDX1 antibody (A03727-1). DDX1 was detected in immunocytochemical section of U20S cells. Enzyme antigen retri

IHC analysis of DDX1 using anti-DDX1 antibody (M03727). DDX1 was detected in a paraffin-embedded section of human prostatic acinar adenocarcinoma tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2 μg/ml mouse anti-DDX1 Antibody (M03727) overnight at 4°C. Peroxidase Conjugated Goat Anti-mouse IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using HRP Conjugated Mouse IgG Super Vision Assay Kit (Catalog # SV0001) with DAB as the chromogen.

M03727 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (M03727). DDX1 was detected in a paraffin-embedded section of human prostatic acinar adenocarc

IHC analysis of DDX1 using anti-DDX1 antibody (M03727). DDX1 was detected in a paraffin-embedded section of human colorectal adenocarcinoma tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2 μg/ml mouse anti-DDX1 Antibody (M03727) overnight at 4°C. Peroxidase Conjugated Goat Anti-mouse IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using HRP Conjugated Mouse IgG Super Vision Assay Kit (Catalog # SV0001) with DAB as the chromogen.

M03727 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (M03727). DDX1 was detected in a paraffin-embedded section of human colorectal adenocarcinoma

IF analysis of DDX1 using anti-DDX1 antibody (M03727). DDX1 was detected in an immunocytochemical section of Hela cells. Enzyme antigen retrieval was performed using IHC enzyme antigen retrieval reagent (AR0022) for 15 mins. The cells were blocked with 10% goat serum. And then incubated with 5 μg/mL mouse anti-DDX1 Antibody (M03727) overnight at 4°C. DyLight®488 Conjugated Goat Anti-Mouse IgG (BA1126) was used as secondary antibody at 1:100 dilution and incubated for 30 minutes at 37°C. Visualize using a fluorescence microscope and filter sets appropriate for the label used.

M03727 · IFIF analysis of DDX1 using anti-DDX1 antibody (M03727). DDX1 was detected in an immunocytochemical section of Hela cells. Enzyme antigen retr

IHC analysis of DDX1 using anti-DDX1 antibody (M03727-2). DDX1 was detected in a paraffin-embedded section of human cervica squamous carcinoma tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2 μg/ml mouse anti-DDX1 Antibody (M03727-2) overnight at 4°C. Peroxidase Conjugated Goat Anti-mouse IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using HRP Conjugated Mouse IgG Super Vision Assay Kit (Catalog # SV0001) with DAB as the chromogen.

M03727-2 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (M03727-2). DDX1 was detected in a paraffin-embedded section of human cervica squamous carcino

IHC analysis of DDX1 using anti-DDX1 antibody (M03727-2). DDX1 was detected in a paraffin-embedded section of human ovarian serous adenocarcinoma tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH 8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2 μg/ml mouse anti-DDX1 Antibody (M03727-2) overnight at 4°C. Peroxidase Conjugated Goat Anti-mouse IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using HRP Conjugated Mouse IgG Super Vision Assay Kit (Catalog # SV0001) with DAB as the chromogen.

M03727-2 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (M03727-2). DDX1 was detected in a paraffin-embedded section of human ovarian serous adenocarc

IHC analysis of DDX1 using anti-DDX1 antibody (M03727-1). DDX1 was detected in paraffin-embedded section of human gastric cancer tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2μg/ml mouse anti-DDX1 Antibody (M03727-1) overnight at 4°C. Biotinylated goat anti-mouse IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1021) with DAB as the chromogen.

M03727-1 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (M03727-1). DDX1 was detected in paraffin-embedded section of human gastric cancer tissue. Hea

IHC analysis of DDX1 using anti-DDX1 antibody (M03727-1). DDX1 was detected in paraffin-embedded section of human pancreatic cancer tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 2μg/ml mouse anti-DDX1 Antibody (M03727-1) overnight at 4°C. Biotinylated goat anti-mouse IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1021) with DAB as the chromogen.

M03727-1 · IHCIHC analysis of DDX1 using anti-DDX1 antibody (M03727-1). DDX1 was detected in paraffin-embedded section of human pancreatic cancer tissue.

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000079785-DDX1/tissue/cerebral+cortex#imid_11610811

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000079785-DDX1/tissue/colon#imid_11610737

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000079785-DDX1/tissue/liver#imid_11610738

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000079785-DDX1/tissue/kidney#imid_11611315

HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA034502; green = DDX1, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

Real IHC / IF data behind the staining-pattern expectations in this section.

Sample controls for DDX1 IHC & IF

🧪Run appendix first: glandular cells should stain (HPA: High in appendix glandular cells). HPA detects DDX1 in all 44 scored tissues, so there is no validated negative tissue or internal negative cell population; no-primary and isotype controls establish background, and any apparently unstained cells on the positive slide should retain counterstain without specific DAB signal (HPA: no negative rows).

Positive control tissue: Appendix (Glandular cells, HPA High)

Negative control tissue: None in HPA: DDX1 is detected in all 44 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show DDX1 in A-431, U-251MG, U2OS, with annotated localisation: Nucleoplasm (supported) (HPA subcellular).

Technical controls: Include a no-primary, secondary-only slide, a concentration-matched rabbit IgG isotype control, and a validated DDX1-knockout specimen processed in parallel (caption: rabbit primary antibody). Block endogenous peroxidase and, if using the caption’s biotin-based detection, endogenous biotin; check appendix inflammatory cells for background DAB staining (caption: biotinylated secondary and SABC–DAB detection).

⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the A03727-1 paraffin-section caption does not state a fixative (caption: fixative not stated). Heat retrieval with EDTA at pH 8.0 was used in the reported IHC example, but its necessity has not been established by a retrieval comparison (caption: EDTA retrieval). Frozen sections have no supplied performance comparison; IF/ICC has separate supporting localization evidence, but is not established as easier (HPA: nucleoplasm and cytosol in ICC-IF).

HPA tissue IHC evidence for DDX1

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — Medium consistency between antibody staining and RNA expression data.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.

Positive expression · recommended positive controls

Tissue	Cell type	Level	Evidence	Source
Appendix	Glandular cells	High	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	High	Protein (IHC)	HPA →
Breast	Adipocytes	High	Protein (IHC)	HPA →
Caudate	Neuronal cells	High	Protein (IHC)	HPA →
Cerebellum	Cells in granular layer	High	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
None in HPA: DDX1 is detected in all 44 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.

Section 3

Advanced DDX1 IHC Tips

Troubleshoot DDX1 staining in paraffin sections by checking retrieval, compartment, controls, and scoring before interpreting biological differences.

How should I optimize retrieval when DDX1 staining is weak?

Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A03727-1). The catalog antibody stained a rat testis paraffin section after this retrieval, although the caption does not state its heating time or fixative (datasheet A03727-1). For a new specimen, compare controlled heating intervals, such as 10 and 20 minutes, while keeping section thickness and detection conditions constant (standard IHC practice). If staining remains weak, test an alternative retrieval buffer as a documented fallback, alongside the EDTA condition and a no-primary control (standard IHC practice).

Could fixation explain inconsistent DDX1 staining across paraffin blocks?

Target-specific fixation sensitivity is unknown: the selected paraffin-section caption does not report a fixative (datasheet A03727-1). Record fixative, time before fixation, fixation duration, and processing for every block, because these variables can change antigen accessibility and tissue morphology (standard IHC practice). If material can be prepared prospectively, compare matched samples fixed for 6 and 24 hours in 10% neutral buffered formalin under the same retrieval and staining conditions (standard IHC practice). Interpret differences as a local optimization result; neither tissue expression patterns nor DDX1 topology establishes a preferred fixation duration (HPA: tissue IHC; UniProt Q92499 topology).

Should I reject DDX1 staining outside the nucleus?

Expect predominantly nuclear staining in tissue: HPA describes ubiquitous nuclear expression, with nucleoplasm as the supported main subcellular location (HPA: tissue IHC; HPA: subcellular). Cytosolic staining can also be plausible because HPA supports an additional cytosolic location and UniProt lists cytoplasm and cytoplasmic granules (HPA: subcellular; UniProt Q92499 localisation). Score nuclear and cytoplasmic signal separately, using the same threshold and a 20× or 40× review of cellular boundaries across specimens (standard IHC practice). Treat isolated cytoplasmic dots cautiously unless their distribution, controls, and experimental stress context support DDX1 granules or foci (UniProt Q92499 localisation; standard IHC practice).

Could DDX1 isoforms or modified residues change antibody staining?

DDX1 has 3 reported isoforms, so determine which sequence the antibody immunogen represents before claiming that staining measures every isoform (UniProt Q92499 isoforms; standard IHC practice). Its annotated regions include an ATP-binding helicase region at residues 2–428 and a C-terminal helicase region at 493–681 (UniProt Q92499 domains). Acetylation is reported at residues 239 and 268, with an alternate annotation at 281, and phosphorylation at 481 (UniProt Q92499 modified residues). Without an epitope map and direct testing, do not attribute weak paraffin staining to a particular isoform or modification; compare a second validated epitope if available (standard IHC practice).

How can I check a DDX1 IHC pattern with multiplex IF?

Use IF as an orthogonal localisation check, pairing DDX1 with a marker for the expected cell type, such as a glial-cell marker when examining cerebral cortex (HPA: High in cerebral-cortex glial cells; standard IF practice). Choose a far-red DDX1 fluorophore when tissue autofluorescence is prominent, and inspect unstained and single-colour controls before interpreting overlap (standard IF practice). DDX1 has no transmembrane segment, while nucleoplasmic and cytosolic locations are supported; permeabilisation therefore serves intracellular antibody access rather than membrane-sided epitope selection (UniProt Q92499 topology; HPA: subcellular). Titrate a mild detergent condition, such as 0.1% Triton X-100 for 5 minutes, and verify morphology and signal retention experimentally (standard IF practice).

What should I check when DDX1 DAB staining is diffuse?

Run a no-primary section through the same secondary, enzyme, and DAB steps to reveal detection-system background (standard IHC practice). The selected paraffin-section example used 10% goat serum blocking, a biotinylated secondary for 30 minutes at 37°C, and DAB development (datasheet A03727-1). Check endogenous peroxidase blocking and, when using biotin-based detection, endogenous biotin as possible contributors to unwanted colour (standard IHC practice). Shorten chromogen development or titrate the primary below the caption’s 1 µg/ml condition only through matched comparisons that preserve a convincing nuclear signal (datasheet A03727-1; HPA: tissue IHC; standard IHC practice).

How should I compare DDX1 staining between tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define a cell population and compartment before scoring, because DDX1 is chiefly nuclear but can also appear in the cytosol (HPA: tissue IHC; HPA: subcellular). For nuclear DAB, report the percentage of positive nuclei and an H-score from intensity categories 0–3, using identical thresholds across sections (standard IHC practice). Normalize counts to evaluable nuclei in the same cell population; for focal signal, report positive-cell density per mm² of viable tissue as a separate measure (standard IHC practice). Exclude folds, damaged edges, and necrotic areas consistently, and record retrieval and staining batches before comparing groups (standard IHC practice).

How do I distinguish genuine DDX1 staining from artefact?

Give most weight to staining within identifiable nuclei in expected cells, since HPA reports ubiquitous nuclear expression and high staining in several specified cell populations (HPA: tissue IHC). Do not automatically discard cytosolic signal: DDX1 has supported cytosolic localisation and can form stress-associated granules or treatment-associated foci (HPA: subcellular; UniProt Q92499 localisation). Check whether colour instead tracks section edges, folds, necrosis, or the no-primary control, including residual endogenous enzyme signal (standard IHC practice). Interpret any apparent group difference against matched processing and compartment-specific scores; HPA rates the tissue evidence “Enhanced” with medium consistency between staining and RNA expression (HPA: tissue IHC; standard IHC practice).

Boster reagents

Best DDX1 / ATP-dependent RNA helicase DDX1 IHC Antibodies

Catalog IHC images show DDX1 in rat testis and human cancer paraffin sections; IF images show human cells, human cancer sections and mouse brain (catalog image captions).

Real IHC data

Anti-DDX1 Antibody ®

Cat # A03727-1

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Real IHC data

Anti-DDX1 ® Antibody (monoclonal, 3I10)

Cat # M03727

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Real IHC data

Anti-DDX1 ® Antibody (monoclonal, 11E5)

Cat # M03727-2

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Real IHC data

Anti-DDX1 ® Antibody (monoclonal, 2D4)

Cat # M03727-1

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A03727-1 has rat testis IHC and human cell IF images (A03727-1 image captions); M03727 has human prostatic adenocarcinoma IHC and human cell IF images (M03727 image captions). M03727-2 has human cervical squamous carcinoma IHC images (M03727-2 image captions); M03727-1 has human gastric cancer IHC images (M03727-1 image captions).

Which to pick: For human tissue IHC, choose M03727: its own caption shows staining in a paraffin section, and it is monoclonal clone 3I10 (M03727 IHC caption; catalog: clone 3I10). For IF/ICC, choose A03727-1, which lists both applications and has IF images of human cells and paraffin sections; for cross-species IHC, its own IHC captions show mouse and rat paraffin sections, while human reactivity is listed separately (A03727-1 applications; IF and IHC captions; catalog reactivity). The fixative is unreported in these paraffin-section captions (catalog IHC captions).

Each figure is that product's own IHC / IF validation image from its datasheet.

References

UniProt Consortium. UniProt entry Q92499 (DDX1_HUMAN, ATP-dependent RNA helicase DDX1).
Human Protein Atlas. DDX1 tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. DDX1 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
Human Protein Atlas. DDX1 antibody validation summary (3 antibodies).
DEAD-box helicase 1 inhibited CD8(+) T cell antitumor activity by inducing PD-L1 expression in hepatocellular carcinoma. Cancer science 2024 — PMC10921000.
ACOD1 deficiency promotes DDX1 methylation-mediated mitochondrial dysfunction and dermal papilla cell senescence in androgenetic alopecia. BMC medicine 2026 — PMC13440255.
DEAD box protein DDX1 promotes colorectal tumorigenesis through transcriptional activation of the LGR5 gene. Cancer science 2018 — PMC6113447.
PRMT1-mediated asymmetric dimethylation of arginine residue 602 in DDX1 promotes cholangiocarcinoma progression. Clinical and molecular hepatology 2026 — PMC13129775.
PubMed PMID:7689221 — UniProt-cited evidence.
PubMed PMID:14702039 — UniProt-cited evidence.
PubMed PMID:15489334 — UniProt-cited evidence.

Immunohistochemistry protocol sheet for DDX1 (ATP-dependent RNA helicase DDX1). Expected localisation Nuclear staining (HPA tissue IHC); cytosolic localization possible (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A03727-1). Validated IHC antibody: A03727-1 at 0.5-1μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Appendix (Glandular cells); negative None in HPA (detected in all 44 tissues); use no-primary + isotype controls. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded rat testis tissue; fixative not specified (datasheet A03727-1); 2. Fixation: Image fixative and duration unreported (datasheet A03727-1); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet A03727-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A03727-1); 8. Primary antibody: Rabbit anti-DDX1, 0.5-1μg/ml (datasheet A03727-1); 9. Primary incubation: Overnight at 4 °C (datasheet A03727-1). Watch for: Fixation: Keep fixation consistent across sections (standard IHC practice; not target-specific); Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A03727-1); Caveat: Active transcription can shift DDX1 into nuclei (UniProt); Isoform / epitope: 3 isoforms; antibody epitope coverage is unspecified (UniProt); Regulation: Higher transcription in neuroectodermal tissues (UniProt). Evidence: UniProt Q92499, HPA tissue IHC · Enhanced, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A03727-1, PMC10921000, PMC6113447. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/DDX1/immunohistochemistry-ihc-guide.