TERF2 / Telomeric repeat-binding factor 2 · IHC design guide

Design Immunohistochemistry for TERF2

Plan TERF2 chromogenic IHC on paraffin sections using the catalog antibody at 0.5–1 μg/ml (datasheet A00650-1). Assess nuclear staining against the HPA tissue profile, including high staining in tonsil germinal center cells (HPA tissue IHC).

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

Immunohistochemistry protocol sheet for TERF2 (IHC for TERF2): expected localisation Nuclear staining in tissue (HPA tissue IHC), antibody A00650-1, validated IHC image, and IHC protocol steps — Printable **TERF2** IHC protocol sheet — expected localisation Nuclear staining in tissue (HPA tissue IHC), antibody A00650-1, controls and protocol steps. Open the full TERF2 IHC guide →

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TERF2 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 in tissue (HPA tissue IHC)
	Staining pattern	Widespread nuclear staining across tissue cell types (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A00650-1)
	Positive control ⓘ	Appendix+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	Keep fixation consistent across sections. (standard IHC practice; not target-specific)
	Caveat	Staining–RNA agreement has medium consistency (HPA tissue IHC)
	Regulation	Low tissue specificity (HPA tissue RNA)
	Isoform / epitope	2 isoforms; verify antibody epitope coverage (UniProt)

Section 1

Recommended TERF2 IHC & IF Protocols

Compare the catalog antibody’s IHC-P protocol (datasheet A00650-1) with four published TERF2 IHC protocols (PMC5190092; PMC11425175; PMC10240986; PMC12881650).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human tonsil tissue; fixative not specified (datasheet A00650-1)
Fixation	Image fixative and duration unreported (datasheet A00650-1); 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 A00650-1); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A00650-1)
Primary antibody	Rabbit anti-TERF2, 0.5-1μg/ml (datasheet A00650-1)
Primary incubation	Overnight at 4 °C (datasheet A00650-1)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A00650-1)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	TERF2-positive staining in lymphoid tissue of appendix (HPA tissue IHC: High). HPA tissue profile: Ubiquitous nuclear expression. No signal in the no-primary control.

💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 for the catalog antibody (datasheet A00650-1); optimize retrieval for other antibodies using their own protocols.

Section 2

What Is the Expected TERF2 Staining Pattern?

TERF2 is a nuclear, telomere-associated protein without a transmembrane segment (UniProt Q15554). In paraffin-section IHC, expect nuclear staining across many cell types (HPA: ubiquitous nuclear expression; IHC reliability Enhanced). Strong examples include lymph-node germinal center cells, fallopian-tube glandular cells and testicular preleptotene spermatocytes (HPA: High). Staining intensity varies by tissue and cell type (HPA: High, Medium and Low observations).

What am I looking at on my slide?
Clear nuclear staining in germinal center cells, with weaker staining in some neighboring cells.	This fits the reported pattern: germinal center cells stain High in lymph node and tonsil (HPA: High), while the broader tissue profile is ubiquitous and nuclear (HPA: tissue IHC). Compare cells within the same section before interpreting weaker nuclei as negative.
Staining is predominantly cytoplasmic or membranous while nuclei remain pale.	That distribution conflicts with nuclear and telomeric localization (UniProt Q15554) and the ubiquitous nuclear IHC profile (HPA: tissue IHC). Review controls, detection chemistry and staining conditions; compartment alone cannot identify the source of an artefact (general IHC practice).
An isolated cell population stains strongly outside the expected nuclear pattern.	TERF2 expression is widespread (UniProt Q15554; HPA: tissue IHC), so an unexpected cell type alone does not prove cross-reactivity. Strong nonnuclear staining, especially in cells lacking matching nuclear signal, warrants checks for nonspecific binding or endogenous detection activity (general IHC practice).
Color is spread across stroma, extracellular spaces or most of the section without crisp nuclei.	Diffuse background cannot be scored as TERF2-positive nuclei against the reported nuclear profile (HPA: tissue IHC). Check the no-primary control and detection reagents, then optimize blocking, antibody concentration and wash conditions (general IHC practice); the payload supplies no TERF2-specific cause of background.
No convincing nuclear signal appears in a known High-staining cell population.	Absent staining in lymph-node germinal center cells or fallopian-tube glandular cells conflicts with their reported High signal (HPA: tissue IHC). First check section quality, assay controls and antibody use (general IHC practice). One negative section does not establish biological absence.

💡Expected TERF2 appearanceCall a result positive when nuclei stain clearly in the examined cells, with strong examples in HPA High populations (HPA: ubiquitous nuclear expression; HPA: High); predominantly cytoplasmic or extracellular color is suspect (UniProt Q15554; general IHC practice).

How each factor affects the staining
Tissue and cell selection	Use a reported High population, such as lymph-node germinal center cells, as a positive reference (HPA: High). Parathyroid glandular cells and cardiomyocytes are reported Low (HPA: Low), so weak staining there is not a validated negative control.
Evidence strength	The tissue profile carries Enhanced IHC reliability, with medium consistency between antibody staining and RNA data (HPA: tissue IHC). HPA001907 and HPA002735 have Enhanced IHC validation; CAB010451 and CAB080271 are Supported (HPA: antibodies). Interpret an unusual pattern alongside controls.
IF/ICC: what pattern is expected?	Expect nucleoplasm and nuclear bodies (HPA: supported ICC-IF locations). UniProt places TERF2 at telomeres in interphase and chromosome ends in metaphase (UniProt Q15554). These observations guide localization; this IHC section provides no IF/ICC protocol.
Molecular features and antibody scope	Two isoforms and several modified residues are recorded (UniProt Q15554), but the supplied evidence does not map an antibody epitope or link these features to IHC intensity. Do not infer an isoform-specific pattern or a retrieval requirement from them.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Expected positive tissue shows no nuclear stain.	The assay may have failed, or the examined section may lack the reported High-staining cells (general IHC practice; HPA: High in specified cell populations).	Confirm the relevant cells are present, review the positive and no-primary controls, then verify antibody dilution and detection steps against the validated IHC procedure (general IHC practice).
Only cytoplasm or membrane stains.	This conflicts with nuclear localization (UniProt Q15554; HPA: ubiquitous nuclear expression); nonspecific staining or detection artefact is possible (general IHC practice).	Compare with a no-primary control, inspect nuclear counterstain and cell boundaries, and optimize blocking and antibody concentration if background persists (general IHC practice).
Most of the section has diffuse color.	High background can obscure the nuclear pattern (general IHC practice; HPA: ubiquitous nuclear expression). The supplied sources do not establish a TERF2-specific background mechanism.	Check no-primary staining and reagent controls; review blocking, washes and chromogen development before scoring nuclei (general IHC practice).
A reported Low population looks nearly unstained.	Low HPA staining indicates a weaker observed signal, not confirmed protein absence (HPA: Low in parathyroid glandular cells, cardiomyocytes and other listed populations).	Compare with a reported High population processed in the same run and score the Low population cautiously (HPA: High and Low observations; general IHC practice).
Strong color appears in an unexpected cell population.	TERF2 is broadly expressed (UniProt Q15554; HPA: ubiquitous nuclear expression), so cell identity alone cannot establish cross-reactivity; endogenous detection activity is also possible (general IHC practice).	Check whether color is nuclear, examine no-primary and detection controls, and repeat with an independently validated antibody if the discrepancy remains (general IHC practice; HPA: antibody validation).
Nuclear signal differs between runs.	Run-to-run differences can reflect section processing, antibody concentration or detection conditions (general IHC practice). No TERF2-specific fixation sensitivity is reported in the supplied UniProt or HPA evidence.	Compare matched positive-control tissue and recorded assay conditions across runs before attributing the difference to TERF2 biology (general IHC practice; HPA: High populations).

Source: UniProt Q15554 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing TERF2 staining

IHC analysis of TRF2 using anti-TRF2 antibody (A00650-1). TRF2 was detected in a paraffin-embedded section of human tonsil 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 1 μg/ml rabbit anti-TRF2 Antibody (A00650-1) 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.

A00650-1 · IHCIHC analysis of TRF2 using anti-TRF2 antibody (A00650-1). TRF2 was detected in a paraffin-embedded section of human tonsil tissue. Heat medi

IHC analysis of TRF2 using anti-TRF2 antibody (A00650-1). TRF2 was detected in a paraffin-embedded section of human lung cancer 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 1 μg/ml rabbit anti-TRF2 Antibody (A00650-1) 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.

A00650-1 · IHCIHC analysis of TRF2 using anti-TRF2 antibody (A00650-1). TRF2 was detected in a paraffin-embedded section of human lung cancer tissue. Heat

M00650 · IFImmunofluorescent analysis using the Antibody at 1:150 dilution.

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000132604-TERF2/tissue/cerebral+cortex#imid_1007920

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000132604-TERF2/tissue/colon#imid_998470

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000132604-TERF2/tissue/liver#imid_998487

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000132604-TERF2/tissue/kidney#imid_998488

HPA · ICC-IF SiHaHuman Protein Atlas immunofluorescence, SiHa, antibody HPA001907; green = TERF2, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for TERF2 IHC & IF

🧪Run lymph node first and score germinal center cells for nuclear TERF2 staining (HPA: High in lymph node germinal center cells; UniProt Q15554: nucleus). HPA detects TERF2 in all 45 scored tissues, so there is no supported negative tissue; use no-primary and isotype controls, and expect any anucleate erythrocytes on the positive slide to lack nuclear staining (HPA: 45/45 tissues detected; standard IHC practice).

Positive control tissue: Appendix (Lymphoid tissue, HPA High)

Negative control tissue: None in HPA: TERF2 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 TERF2 in SiHa, U-251MG, U2OS, U2OS, siRNA 2 (10x), U2OS, scrambled (10x), U2OS, siRNA 1 (10x), with annotated localisation: Nucleoplasm (supported), Nuclear bodies (supported) (HPA subcellular).

Technical controls: Include a no-primary, secondary-only slide and a rabbit IgG isotype control matched to the primary antibody’s clonality where applicable; assess biological specificity with a TERF2 knockout control processed alongside the specimen (selected-SKU caption: rabbit primary; standard IHC practice). Quench endogenous peroxidase for chromogenic detection and check background in lymphoid tissue with the no-primary slide (standard IHC practice).

⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected-SKU paraffin-section caption does not state a fixative (selected-SKU caption: fixative unreported). The caption provides a practical IHC starting point: heat retrieval in EDTA at pH 8.0, followed by 1 μg/ml primary antibody overnight at 4°C; retrieval dependence has not been established (selected-SKU caption). Frozen sections are not established as easier by the supplied evidence; ICC-IF offers a nuclear localization readout in imaged cells, while lymphoid-tissue background should be checked with the no-primary control (HPA: nucleoplasm and nuclear bodies; HPA: ICC-IF images; standard IHC practice).

HPA tissue IHC evidence for TERF2

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	Lymphoid tissue	High	Protein (IHC)	HPA →
Fallopian tube	Glandular cells	High	Protein (IHC)	HPA →
Lung	Alveolar cells type I	High	Protein (IHC)	HPA →
Lymph node	Germinal center cells	High	Protein (IHC)	HPA →
Testis	Preleptotene spermatocytes	High	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
None in HPA: TERF2 is detected in all 45 scored tissues. Use a no-primary (secondary-only) and an isotype control instead.

Section 3

Advanced TERF2 IHC Tips

Troubleshoot TERF2 staining in paraffin section IHC using nuclear localisation, the catalog antibody’s tissue result, and appropriate controls.

Which retrieval conditions should I try first for weak TERF2 staining in paraffin sections?

Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin sections (datasheet A00650-1). The catalog antibody produced a tonsil tissue image after this retrieval, followed by 1 μg/ml primary antibody overnight at 4°C (datasheet A00650-1). If nuclear signal is weak, compare retrieval heating and cooling conditions on adjacent sections while holding antibody concentration and detection constant (standard IHC practice). Include a known positive tonsil section in each comparison because germinal center cells show high TERF2 staining (HPA: High in tonsil germinal center cells). Judge improvement by nuclear signal and tissue preservation together, since TERF2 is a nuclear protein (UniProt Q15554 localisation).

Could fixation explain inconsistent TERF2 staining between paraffin blocks?

The catalog image identifies a paraffin embedded tonsil section but does not state its fixative, so target specific fixation sensitivity is unknown (datasheet A00650-1). Record each block’s fixative and processing history before attributing a staining difference to TERF2 biology (standard IHC practice). Compare adjacent sections from blocks with known processing histories using the same pH 8.0 EDTA retrieval and detection run (datasheet A00650-1; standard IHC practice). Check whether nuclear staining and tissue morphology change together across the comparison, using tonsil germinal center cells as a positive reference (HPA: High in tonsil germinal center cells). Avoid assigning a TERF2 specific fixation effect without a controlled comparison.

Should TERF2 look diffuse or punctate in chromogenic tissue IHC?

Evaluate TERF2 primarily within nuclei: it localises to the nucleus and chromosome telomeres, including chromosome ends during metaphase (UniProt Q15554 localisation). Supported subcellular observations place it in the nucleoplasm and nuclear bodies, so nuclear staining can include discrete foci (HPA subcellular: supported nucleoplasm and nuclear bodies). In chromogenic sections, record both nuclear intensity and pattern, but do not identify an individual DAB focus as a telomere without an independent telomere assay (standard IHC interpretation). Prioritise correctly localised signal in positive reference cells, such as tonsil germinal center cells, when assessing a weak specimen (HPA: High in tonsil germinal center cells). Predominantly cytoplasmic staining warrants a specificity check (UniProt Q15554 localisation).

Can an epitope difference explain disagreement between TERF2 antibodies?

TERF2 has 2 annotated isoforms and a myb type DNA binding domain at residues 484–541 (UniProt Q15554 isoforms and domains). The supplied catalog image does not map the antibody epitope, so it cannot establish which isoforms or modified forms that antibody recognises (datasheet A00650-1). Document the mapped epitope and isoform coverage for each antibody before comparing their nuclear staining patterns (standard IHC validation practice). TERF2 also has reported modified residues, including methylated arginines near positions 59–60 and phosphorylation at 230 and 365 (UniProt Q15554 modified residues). Those annotations alone do not establish an effect on IHC staining; test discordant reagents on matched sections with appropriate controls.

How should I follow a TERF2 IHC result with multiplex IF?

For a multiplex follow up, pair TERF2 with a marker for the expected cell population, such as a germinal center B cell marker in tonsil, and score signal within matched nuclei (HPA: High in tonsil germinal center cells; standard immunophenotyping practice). Choose a spectrally separated red or far red fluorophore after checking the tissue’s autofluorescence and single stain controls (standard IF practice). TERF2 is nuclear and has no transmembrane segment, so permeabilisation must permit antibody access to the nucleus rather than target a membrane facing epitope (UniProt Q15554 localisation and topology). Optimise permeabilisation and nuclear counterstain in the IF preparation itself (standard IF practice). The catalog caption reports paraffin section IHC and leaves fixation unstated, so it does not establish IF fixation conditions (datasheet A00650-1).

How can I separate TERF2 signal from chromogenic background?

The catalog tonsil example used a biotinylated secondary antibody, a streptavidin biotin complex, and DAB, so inspect background at each stage of that detection workflow (datasheet A00650-1). Include a section without primary antibody to reveal secondary, endogenous biotin, or peroxidase associated signal; apply appropriate biotin and peroxidase blocking controls where indicated (standard IHC practice). Also compare tissue edges and damaged regions with intact central tissue, because uneven reagent exposure can mislead interpretation (standard IHC practice). Genuine TERF2 staining should be evaluated in nuclei, especially in a positive reference such as tonsil germinal center cells (UniProt Q15554 localisation; HPA: High in tonsil germinal center cells).

What should I measure when comparing TERF2 across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and anatomical region before scoring, then count TERF2 positive nuclei rather than total brown area (UniProt Q15554 localisation; standard IHC quantification practice). Report the percentage of positive nuclei and, when intensity matters, a nuclear H score using intensity categories 0–3 weighted by their cell percentages (standard IHC quantification practice). Normalise positive cell counts to the number of evaluable nuclei, or report positive cell density per mm² of viable tissue when cellularity differs (standard IHC quantification practice). Use identical thresholds, counterstaining, imaging, and region selection across sections, with a positive reference on each run (standard IHC practice). HPA reports medium consistency between staining and RNA expression, so treat intensity differences as measurements requiring controls, not direct expression calibration (HPA: Enhanced reliability description).

When is a TERF2 positive DAB pattern convincing?

A convincing result places DAB signal in intact nuclei and reproduces the expected positive reference pattern, including tonsil germinal center cells (UniProt Q15554 localisation; HPA: High in tonsil germinal center cells). Predominantly cytoplasmic staining conflicts with the reported nuclear and telomeric localisation and should prompt antibody and detection controls (UniProt Q15554 localisation). Compare suspect areas with section interiors and exclude necrotic or edge damaged regions from interpretation (standard IHC practice). Check a no primary control and peroxidase blocking control when diffuse brown deposits could reflect the chromogenic workflow (standard IHC practice). Nuclear staining supports TERF2 detection, but DAB staining alone does not prove that each visible focus occupies a telomere (UniProt Q15554 localisation; standard IHC interpretation).

Boster reagents

Best TERF2 / Telomeric repeat-binding factor 2 IHC Antibodies

Anti-TERF2 antibodies have IHC images from human tonsil and lung cancer paraffin sections (A00650-1 IHC captions) and an IF image with no specimen identified (M00650 IF caption).

Real IHC data

Anti-TRF2/TERF2 Antibody ®

Cat # A00650-1

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Real IF data Immunofluorescent analysis using the Antibody at 1:150 dilution.

Anti-TRF2 Monoclonal Antibody

Cat # M00650

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A00650-1 shows IHC staining in human tonsil and lung cancer paraffin sections (A00650-1 IHC captions). M00650 lists human IHC and IF/ICC applications (M00650 catalog), but its IF image does not identify the specimen (M00650 IF caption).

Which to pick: Choose A00650-1 for human paraffin-section chromogenic IHC: its images document 1 μg/ml primary antibody, EDTA retrieval at pH 8.0, and DAB detection (A00650-1 IHC captions); the fixative is unreported (A00650-1 IHC captions). For IF/ICC, choose M00650, a rabbit monoclonal with human reactivity and listed IF/ICC applications (M00650 catalog). For work involving rat samples, A00650-1 lists rat reactivity (A00650-1 catalog), although its displayed IHC evidence is from human tissue (A00650-1 IHC captions).

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

References

UniProt Consortium. UniProt entry Q15554 (TERF2_HUMAN, Telomeric repeat-binding factor 2).
Human Protein Atlas. TERF2 tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. TERF2 subcellular location (ICC-IF): Localized to the nucleoplasm and nuclear bodies..
Human Protein Atlas. TERF2 antibody validation summary (4 antibodies).
Telomeric repeat-binding factor 2: a marker for survival and anti-EGFR efficacy in oral carcinoma. Oncotarget 2016 — PMC5190092.
Expression and functional analyses of TERF2 in esophageal carcinoma. Heliyon 2024 — PMC11425175.
The telomeric protein TERF2/TRF2 impairs HMGB1-driven autophagy. Autophagy 2023 — PMC10240986.
The role of cellular senescence-related genes in ischemia-reperfusion injury and the identification of their biomarkers. Scientific reports 2026 — PMC12881650.
PubMed PMID:15616553 — UniProt-cited evidence.
PubMed PMID:15489334 — UniProt-cited evidence.
PubMed PMID:9326950 — UniProt-cited evidence.