HTATSF1 / 17S U2 SnRNP complex component HTATSF1 · IHC design guide

Design Immunohistochemistry for HTATSF1

Plan HTATSF1 chromogenic IHC around ubiquitous nuclear staining (HPA tissue IHC). This guide pairs positive tissue choices, including bone marrow hematopoietic cells (HPA tissue IHC), with the catalog antibody’s paraffin-section starting range of 2–5 μg/ml (datasheet A07890-2).

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

Immunohistochemistry protocol sheet for HTATSF1 (IHC for HTATSF1): expected localisation Ubiquitous nuclear staining (HPA tissue IHC), antibody A07890-2, validated IHC image, and IHC protocol steps — Printable **HTATSF1** IHC protocol sheet — expected localisation Ubiquitous nuclear staining (HPA tissue IHC), antibody A07890-2, controls and protocol steps. Open the full HTATSF1 IHC guide →

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HTATSF1 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	Ubiquitous nuclear staining (HPA tissue IHC)
	Staining pattern	Nuclear staining across tissue cell types (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A07890-2)
	Positive control ⓘ	Adipose tissue+4 more · see all
	Negative control ⓘ	None in HPA (detected in all 45 tissues); use no-primary + isotype controls

Important caveats

Reasons your staining may differ from the expected pattern.

	Fixation	Matched tissue-IHC evidence does not establish the fixation claim. Validate the specimen-specific method before use. (selected-SKU IHC image A07890-2)
	Caveat	Ubiquitous staining limits negative-tissue controls (HPA tissue IHC)
	Regulation	Widely expressed (UniProt)
	Isoform / epitope	No isoforms annotated; chain spans residues 2–755 (UniProt)

Section 1

Recommended HTATSF1 IHC & IF Protocols

The catalog antibody uses heat-mediated EDTA pH 8.0 retrieval (datasheet A07890-2). One published IHC protocol for FFPE tissue microarray sections is included (PMC8179927).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded mouse brain tissue; fixative not specified (datasheet A07890-2)
Fixation	Image fixative and duration unreported (datasheet A07890-2); 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 A07890-2); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A07890-2)
Primary antibody	Rabbit anti-HTATSF1, 2-5 μg/ml (datasheet A07890-2)
Primary incubation	Overnight at 4 °C (datasheet A07890-2)
Detection	HRP-conjugated secondary, DAB chromogen (datasheet A07890-2)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	HTATSF1-positive staining in adipocytes of adipose tissue (HPA tissue IHC: High). HPA tissue profile: Ubiquitous nuclear expression. No signal in the no-primary control.

💡Decision noteStart with EDTA pH 8.0 retrieval for the catalog antibody (datasheet A07890-2); the published protocol used heated TRIS-EDTA for 30 min (PMC8179927).

Section 2

What Is the Expected HTATSF1 Staining Pattern?

HTATSF1 should stain nuclei across many cell types in paraffin sections: HPA describes ubiquitous nuclear expression and low tissue specificity (HPA: tissue IHC), while UniProt places it in the nucleus and chromosome and reports no transmembrane segment (UniProt O43719: subcellular location and topology). HPA rates the tissue pattern Supported, with medium consistency between antibody staining and RNA expression (HPA: tissue IHC).

What am I looking at on my slide?
Clear nuclear staining in adipocytes, appendix glandular cells, or bone marrow hematopoietic cells (HPA: High in each).	This fits the reported tissue pattern when nuclei, rather than surrounding cytoplasm, carry the chromogen (HPA: ubiquitous nuclear expression). Compare intensity within the same staining run; HPA's High categories do not prescribe an absolute color intensity for every section (HPA: tissue IHC; general IHC practice).
Cytoplasmic or membrane staining dominates while nuclei remain weak or blank (HPA: nuclear tissue pattern).	That compartment conflicts with the expected nuclear pattern and with the lack of a transmembrane segment (HPA: tissue IHC; UniProt O43719: topology). Treat it as a possible artefact; inspect morphology and controls before assigning it to HTATSF1 (general IHC practice).
An unexpected cell population stains strongly, especially outside its nuclei (HPA: ubiquitous nuclear expression).	Cross-reactivity or endogenous chromogenic detection activity is possible (general IHC practice). Cell identity alone cannot establish a false positive: HPA reports low tissue specificity and supplies no negative cell population here (HPA: tissue IHC). Check compartment and detection controls.
Chromogen spreads across tissue or appears in spaces without recognizable nuclei (general IHC practice).	Diffuse background prevents confident nuclear scoring (general IHC practice). Review blocking, washes, detection chemistry, and exposure or development time with appropriate controls; HPA's nuclear pattern does not support interpreting this haze as HTATSF1 (HPA: tissue IHC; general IHC practice).
Nuclei lack signal in an appendix section whose glandular cells are expected to stain High (HPA: appendix glandular cells).	A negative result there warrants a run-level check before a biological conclusion (general IHC practice). HPA's Supported rating reflects medium consistency with RNA data, so the tissue category is a useful expectation rather than a guarantee for every specimen (HPA: tissue IHC).

💡Expected HTATSF1 appearanceCall the IHC result positive when recognizable nuclei stain in the expected broad range of cells, with conspicuous signal in HPA High populations such as bone marrow hematopoietic cells; predominantly membrane, cytoplasmic, or structureless staining is suspect (HPA: tissue IHC; UniProt O43719: topology; general IHC practice).

How each factor affects the staining
Tissue distribution and confidence (HPA: tissue IHC)	The profile is ubiquitous and nuclear, with low tissue specificity; the tissue evidence is Supported and has medium antibody–RNA consistency (HPA: tissue IHC). Do not designate an unlisted tissue as negative from this payload.
Antibody validation (HPA: HPA000504)	The listed antibody is rated Supported for IHC and Enhanced for ICC (HPA: HPA000504). Those are application-specific ratings; the ICC result does not establish a stronger IHC rating.
IF/ICC: what pattern is expected? (HPA: subcellular ICC-IF)	Nucleoplasmic signal is the reported enhanced location in ICC-IF (HPA: subcellular ICC-IF). Use that as a localisation comparison; IF/ICC procedure belongs to its own guide.
Chromosome and DNA damage context (UniProt O43719: subcellular location)	UniProt also lists chromosome localisation and S-phase recruitment to DNA damage sites after interaction with poly-ADP-ribosylated RPA1 (UniProt O43719). This does not establish a routine punctate pattern in untreated tissue.
Antigen retrieval and epitope (general IHC practice)	Retrieval conditions can be checked against the catalog antibody's IHC-P instructions (general IHC practice). No target-specific retrieval response, epitope position, or fixation sensitivity is supplied by UniProt or HPA here.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Little or no nuclear staining in a reported High population (HPA: tissue IHC).	The staining run or antigen detection may have failed; a single blank section does not resolve the cause (general IHC practice).	Check an in-run positive section, the catalog antibody's IHC-P instructions, retrieval, dilution, and detection steps (general IHC practice). Do not infer HTATSF1-specific fixation sensitivity from HPA's tissue ratings.
Strong cytoplasmic or membrane signal overwhelms nuclei (HPA: nuclear tissue pattern).	Nonspecific binding or detection background is possible (general IHC practice); HTATSF1 has no transmembrane segment (UniProt O43719: topology).	Compare a detection-only control, review blocking and washes, and score nuclear signal separately from background (general IHC practice).
A surprising cell population appears positive.	Cross-reactivity or endogenous detection activity may contribute (general IHC practice), while broad expression remains plausible (HPA: low tissue specificity).	Confirm the cells by morphology and nuclear localisation, then inspect detection controls (general IHC practice). Avoid labeling a population negative solely because it is absent from HPA's example list.
Diffuse stain obscures nuclear boundaries.	Background from blocking, washing, or chromogen development may prevent localisation (general IHC practice).	Review those steps and the counterstain alongside a detection control; interpret only clearly bounded nuclear staining (general IHC practice; HPA: ubiquitous nuclear expression).
Sections in one run differ sharply in apparent intensity.	Section and run variation can affect visual comparisons (general IHC practice); HPA High labels are categorical tissue observations (HPA: tissue IHC).	Compare like cells with matched processing and controls before attributing intensity differences to biology (general IHC practice).
Small nuclear foci are proposed as a DNA damage readout.	UniProt reports recruitment to damage sites during S-phase, but the supplied HPA tissue profile establishes a broad nuclear pattern (UniProt O43719; HPA: tissue IHC).	Score routine IHC for nuclear localisation; reserve a damage-site interpretation for an experiment with independent damage and cell-cycle evidence (general IHC practice).

Source: UniProt O43719 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing HTATSF1 staining

IHC analysis of HTATSF1 using anti-HTATSF1 antibody (A07890-2). HTATSF1 was detected in a paraffin-embedded section of mouse brain 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 rabbit anti-HTATSF1 Antibody (A07890-2) overnight at 4°C. Peroxidase Conjugated Goat Anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using HRP Conjugated Rabbit IgG Super Vision Assay Kit (Catalog # SV0002) with DAB as the chromogen.

A07890-2 · IHCIHC analysis of HTATSF1 using anti-HTATSF1 antibody (A07890-2). HTATSF1 was detected in a paraffin-embedded section of mouse brain tissue. H

IF analysis of HTATSF1 using anti-HTATSF1 antibody (A07890-2). HTATSF1 was detected in a paraffin-embedded section of mouse brain 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 5 μg/mL rabbit anti-HTATSF1 Antibody (A07890-2) overnight at 4°C. DyLight®594 Conjugated Goat Anti-Rabbit IgG (BA1142) was used as secondary antibody at 1:500 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.

A07890-2 · IFIF analysis of HTATSF1 using anti-HTATSF1 antibody (A07890-2). HTATSF1 was detected in a paraffin-embedded section of mouse brain tissue. He

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000102241-HTATSF1/tissue/cerebral+cortex#imid_159402

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000102241-HTATSF1/tissue/colon#imid_159336

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000102241-HTATSF1/tissue/liver#imid_159337

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000102241-HTATSF1/tissue/kidney#imid_159346

HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA000504; green = HTATSF1, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for HTATSF1 IHC & IF

🧪Start with appendix: its glandular cells score High and should show nuclear staining (HPA: High in appendix glandular cells; UniProt O43719: nucleus). HPA detects HTATSF1 in all 45 scored tissues, so there is no validated negative tissue or internal negative cell population; use no-primary and isotype controls to judge background, and do not label weakly stained cells on the positive slide as true negatives (HPA: no negative rows; detected in all 45 scored tissues).

Positive control tissue: Adipose tissue (Adipocytes, HPA High)

Negative control tissue: None in HPA: HTATSF1 is detected in all 45 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 HTATSF1 in A-431, U-251MG, U2OS, U2OS, siRNA 1 (10x), U2OS, siRNA 1 (40x), U2OS, scrambled (10x), U2OS, scrambled (40x), with annotated localisation: Nucleoplasm (enhanced) (HPA subcellular).

Technical controls: Run a no-primary, secondary-only section and a concentration-matched rabbit IgG isotype control, matching clonality if known; use HTATSF1 knockout tissue as a biological negative if available (selected-SKU caption: rabbit primary; standard IHC controls). For appendix sections, block endogenous peroxidase before HRP/DAB detection and check that any inflammatory cells do not contribute background staining (selected-SKU caption: HRP/DAB; standard IHC practice).

⚠️Feasibility: The selected-SKU paraffin-section caption reports heat retrieval in EDTA at pH 8.0, but does not establish whether retrieval is required; its fixative is unreported (selected-SKU caption). No target-specific fixation window or fixation effect is reported in the supplied evidence, and it does not establish whether frozen sections or IF would be easier (supplied target/application evidence). Score glandular cell nuclei against the controls, taking care that endogenous peroxidase in inflammatory cells can complicate HRP/DAB interpretation in appendix (HPA: High in appendix glandular cells; UniProt O43719: nucleus; standard IHC practice).

HPA tissue IHC evidence for HTATSF1

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Supported — 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
Adipose tissue	Adipocytes	High	Protein (IHC)	HPA →
Adrenal gland	Glandular cells	High	Protein (IHC)	HPA →
Appendix	Glandular cells	High	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	High	Protein (IHC)	HPA →
Breast	Adipocytes	High	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
None in HPA: HTATSF1 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.

Section 3

Advanced HTATSF1 IHC Tips

Troubleshoot HTATSF1 chromogenic IHC by checking retrieval, nuclear staining, controls, and scoring in matched paraffin sections.

How should I optimise retrieval when nuclear HTATSF1 staining is weak?

Start with heat-mediated antigen retrieval in EDTA pH 8.0 for paraffin sections (datasheet A07890-2). The selected mouse brain image used this retrieval, followed by a 10% goat serum block and 2 μg/ml primary antibody overnight at 4°C (caption A07890-2). Keep heating duration, cooling, section thickness, and DAB development consistent across sections because retrieval changes can alter apparent nuclear intensity (standard IHC practice). If staining remains weak, compare retrieval times on adjacent sections while retaining EDTA pH 8.0, and assess nuclear HTATSF1 against a no-primary control (UniProt O43719; standard IHC practice).

Can fixation explain weak HTATSF1 staining in paraffin sections?

The selected A07890-2 caption identifies a paraffin section but does not state its fixative, so target-specific fixation sensitivity remains unknown (caption A07890-2). For a new chromogenic IHC series, record the fixative, fixation duration, tissue thickness, and processing conditions before attributing weak staining to the antibody (standard IHC practice). Compare sections processed under defined conditions using the same EDTA pH 8.0 retrieval and 2 μg/ml primary antibody overnight at 4°C (caption A07890-2). Evaluate morphology and nuclear-to-background contrast together; the ubiquitous nuclear tissue profile is a localisation reference, not evidence of a fixation response (HPA tissue IHC).

Which staining pattern should count as HTATSF1 in chromogenic IHC?

Prioritise staining within intact nuclei because HTATSF1 is nuclear and chromosomal, and HPA describes ubiquitous nuclear tissue expression (UniProt O43719; HPA tissue IHC). HPA further places the protein in the nucleoplasm, which supports evaluating intranuclear DAB against adjacent cytoplasm (HPA subcellular; standard IHC practice). The 2 μg/ml A07890-2 mouse brain image demonstrates a paraffin-section workflow, but its caption does not establish a compartment-specific scoring threshold (caption A07890-2). Compare viable cells with nearby no-primary controls, and investigate predominantly cytoplasmic, extracellular, or tissue-edge staining before calling it HTATSF1 (standard IHC practice).

Could epitope accessibility or modifications change the HTATSF1 IHC pattern?

UniProt lists 0 isoforms for this record and places HTATSF1 RNA-recognition motifs at residues 133–218 and 264–349 (UniProt O43719). It also lists modified residues, including phosphoserines at 387, 403, and 407, but the supplied antibody caption does not identify its epitope (UniProt O43719; caption A07890-2). Therefore, do not assign a staining difference to an isoform or a modification without epitope information and independent evidence (standard IHC interpretation). First compare matched sections with consistent EDTA pH 8.0 retrieval and primary incubation, then assess whether any difference persists in intact nuclei (datasheet A07890-2; standard IHC practice).

How can IF help check an unexpected chromogenic HTATSF1 result?

Use IF as a localisation cross-check for chromogenic IHC: HPA reports enhanced nucleoplasmic HTATSF1 localisation and high staining in caudate neuronal cells (HPA subcellular; HPA tissue IHC). For caudate sections, multiplex with a validated neuronal marker and check whether HTATSF1 signal falls within the marked cells' nuclei (HPA tissue IHC; standard IF practice). Choose a spectrally distinct, preferably far-red reporter after checking tissue autofluorescence, and include single-label controls for channel bleed-through (standard IF practice). HTATSF1 has no transmembrane segment, so use permeabilisation appropriate for access to its nuclear epitope; compare the resulting pattern with nuclear DAB staining, without assuming the IHC dilution transfers to IF (UniProt O43719; standard IF practice).

What should I check when HTATSF1 DAB staining is diffuse?

First compare the stained section with a no-primary control to identify signal caused by detection reagents or endogenous peroxidase (standard IHC practice). The selected protocol used a 10% goat serum block, 2 μg/ml primary overnight at 4°C, and a peroxidase-linked secondary for 30 minutes at 37°C before DAB development (caption A07890-2). Check peroxidase blocking, wash consistency, and DAB development on matched sections before changing the primary concentration (standard IHC practice). Since HPA reports ubiquitous nuclear staining, judge background by its compartment and control-slide signal rather than assuming widespread nuclear positivity is nonspecific (HPA tissue IHC; standard IHC practice).

How should I quantify HTATSF1 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define viable cell populations and score nuclear DAB only, consistent with the reported ubiquitous nuclear tissue profile (HPA tissue IHC; standard IHC practice). For intensity analysis, grade nuclei 0–3 and calculate an H-score as the sum of each grade multiplied by its percentage of cells, yielding 0–300 (standard IHC practice). Alternatively, report the percentage of positive nuclei or positive nuclear density per mm², with thresholds set before comparing groups (standard IHC practice). Normalise counts to viable nucleated cells or assessed tissue area, and keep retrieval, DAB development, imaging, and scoring rules consistent across sections (standard IHC practice).

How can I distinguish true HTATSF1 staining from artefact?

A credible result places DAB in intact nuclei, matching UniProt's nuclear localisation and HPA's ubiquitous nuclear tissue profile (UniProt O43719; HPA tissue IHC). High staining in caudate neuronal cells and cerebellar Bergmann glial nuclei provides documented tissue context, though HPA rates agreement with RNA data as medium (HPA tissue IHC). Treat signal concentrated at section edges, within necrotic areas, or outside cells as suspect, and compare it with morphology and a no-primary control (standard IHC practice). Check endogenous peroxidase when DAB persists without primary antibody; do not infer S-phase DNA damage recruitment from ordinary nuclear staining alone (standard IHC practice; UniProt O43719).

Boster reagents

Best HTATSF1 / 17S U2 SnRNP complex component HTATSF1 IHC Antibodies

A07890-2 has paraffin-section mouse brain IHC and mouse and rat brain IF images; human, mouse and rat reactivity is listed (catalog IHC/IF captions; catalog reactivity).

Real IHC data

Anti-HTATSF1 Antibody ®

Cat # A07890-2

View product →

Only A07890-2 renders: its IHC image shows staining in a paraffin-embedded mouse brain section after EDTA pH 8.0 retrieval and DAB detection (catalog IHC caption). Its IF images show paraffin-embedded mouse and rat brain sections; human reactivity is listed without a human IHC or IF image (catalog IF captions; catalog reactivity).

Which to pick: For tissue IHC, choose A07890-2 based on its mouse brain paraffin-section image; the fixative is unreported (catalog IHC caption). For tissue IF, A07890-2 has mouse and rat brain images, while M07890 lists ICC/IF and is a rabbit monoclonal clone 25H56 without an IHC or IF image (catalog IF captions; M07890 applications, clone and image fields). Both list human, mouse and rat reactivity for cross-species planning, but pictured evidence is limited to A07890-2 in mouse IHC and mouse and rat IF (catalog reactivity; catalog IHC/IF captions).

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

References

UniProt Consortium. UniProt entry O43719 (HTSF1_HUMAN, 17S U2 SnRNP complex component HTATSF1).
Human Protein Atlas. HTATSF1 tissue IHC expression (reliability: Supported).
Human Protein Atlas. HTATSF1 subcellular location (ICC-IF): Localized to the nucleoplasm..
Human Protein Atlas. HTATSF1 antibody validation summary (1 antibodies).
CK2-HTATSF1-TOPBP1 signaling axis modulates tumor chemotherapy response. The Journal of biological chemistry 2024 — PMC11208909.
Metabolic protein phosphoglycerate kinase 1 confers lung cancer migration by directly binding HIV Tat specific factor 1. Cell death discovery 2021 — PMC8179927.
PubMed PMID:8849451 — UniProt-cited evidence.
PubMed PMID:15772651 — UniProt-cited evidence.
PubMed PMID:15489334 — UniProt-cited evidence.