FAM120A / Constitutive coactivator of PPAR-gamma-like protein 1 · IHC design guide

Design Immunohistochemistry for FAM120A

Plan FAM120A IHC-P around the general cytoplasmic tissue pattern (HPA tissue IHC). The guide identifies high-staining colon glandular cells and adipocytes with no detected staining as comparison populations (HPA tissue IHC).

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

Immunohistochemistry protocol sheet for FAM120A (IHC for FAM120A): expected localisation General cytoplasmic staining in tissue sections (HPA tissue IHC), antibody M09208, validated IHC image, and IHC protocol steps — Printable **FAM120A** IHC protocol sheet — expected localisation General cytoplasmic staining in tissue sections (HPA tissue IHC), antibody M09208, controls and protocol steps. Open the full FAM120A IHC guide →

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FAM120A 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	General cytoplasmic staining in tissue sections (HPA tissue IHC)
	Staining pattern	Cytoplasmic staining across multiple tissue cell types (HPA tissue IHC)
	Antigen retrieval	Citrate pH 6 HIER, heat-mediated (datasheet M09208)
	Positive control ⓘ	Appendix+4 more · see all
	Negative control ⓘ	Adipose tissue

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 M09208)
	Caveat	Medium staining–RNA consistency; verify specificity (HPA tissue IHC)
	Regulation	Widely expressed; regulation unspecified (UniProt)
	Isoform / epitope	5 isoforms; epitope coverage is unknown (UniProt)

Section 1

Recommended FAM120A IHC & IF Protocols

Compare the catalog antibody’s IHC-P protocol (datasheet M09208) with published bladder tissue microarray (PMC13602547) and patient and mouse tissue protocols (PMC10987584).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Formaldehyde-fixed, paraffin-embedded tissue sections (datasheet M09208; sample unspecified)
Fixation	Image formalin-fixed; duration unreported (datasheet M09208); verify before use.
Sectioning	4–5 µm sections on charged slides (standard)
Deparaffinisation	Xylene, graded ethanol series to water (standard)
Antigen retrieval	Heat retrieval: Citrate pH 6 (datasheet M09208); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% normal serum of the secondary host, 30 min, room temperature (standard)
Primary antibody	Mouse monoclonal (clone 1501CT803.19.85.5) anti-FAM120A, 1:25 (datasheet M09208)
Primary incubation	1 hours at 37°C (datasheet M09208)
Detection	HRP-polymer secondary, DAB chromogen 5–10 min (standard)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	FAM120A-positive staining in glandular cells of appendix (HPA tissue IHC: High). HPA tissue profile: General cytoplasmic expression. No signal in the no-primary control.

💡Decision noteStart with heat-mediated citrate retrieval at pH 6 (datasheet M09208); the published excerpts do not specify retrieval conditions (PMC13602547; PMC10987584).

Section 2

What Is the Expected FAM120A Staining Pattern?

FAM120A should appear mainly in the cytoplasm of many cell types, including glandular epithelium, respiratory epithelium, neurons and glia (HPA: general cytoplasmic expression; HPA: High in these cells). Its cytosolic and cell membrane annotations, with no transmembrane segment, support a predominantly nonnuclear pattern (UniProt Q9NZB2: localisation and topology). HPA rates tissue IHC Approved, with medium agreement between staining and RNA data and external verification pending (HPA: tissue IHC reliability).

What am I looking at on my slide?
Cytoplasmic chromogen in glandular cells of appendix, breast, cervix or colon; adjacent cells vary in intensity.	This fits the reported distribution: HPA scores those glandular populations High and describes general cytoplasmic expression (HPA: tissue IHC). Judge staining in the named cells, rather than requiring uniform colour across the section. Approved IHC reliability still carries a medium consistency and pending verification caveat (HPA: tissue IHC reliability).
Strong, predominantly nuclear staining with little cytoplasmic signal.	Treat this as a compartment mismatch: the expected tissue IHC pattern is cytoplasmic, and HPA ICC-IF places FAM120A in the cytosol (HPA: tissue IHC; HPA: subcellular). Review controls and detection conditions before assigning nuclear staining to FAM120A (general IHC practice).
Adipocytes stain strongly while the expected glandular or neural cells do not.	HPA reports FAM120A as Not detected in adipocytes, while several glandular and neural populations score High (HPA: tissue IHC). That reversal raises concern for antibody cross-reactivity or endogenous detection activity; it does not prove either cause (general IHC interpretation).
Chromogen spreads through stroma, lumina or much of the section without a cellular cytoplasmic pattern.	Diffuse colour is difficult to score as target staining because HPA describes a cellular, general cytoplasmic pattern (HPA: tissue IHC). Check reagent-only background, endogenous detection activity and nonspecific antibody binding with appropriate controls; these are general IHC checks, not established FAM120A-specific effects (general IHC practice).
No convincing signal in the expected cell population of a known-positive section.	An absent signal conflicts with HPA's High calls for the specified cells, but a single negative section cannot establish absent protein (HPA: tissue IHC). Confirm that the tissue contains those cells, then review antibody application, retrieval and detection controls (general IHC practice).

💡Expected FAM120A appearanceCall a result positive when cytoplasmic staining is prominent in an HPA High cell population, such as colon glandular cells; dominant nuclear colour or strong adipocyte staining is suspect (HPA: tissue IHC; general IHC interpretation).

How each factor affects the staining
Cell population and tissue context	HPA reports High staining in glandular cells of appendix, breast, cervix and colon, respiratory epithelium of bronchus, and selected neurons and glia; adipocytes are Not detected (HPA: tissue IHC). Compare the named cells rather than whole-section colour. These calls describe observed staining, not a universal positive or negative guarantee (HPA: tissue IHC reliability).
Expected compartment and stimulus context	HPA tissue IHC describes general cytoplasmic expression, and HPA ICC-IF identifies the cytosol as the main location (HPA: tissue IHC; HPA: subcellular). UniProt also annotates cell membrane localisation and cytosol-to-plasma-membrane movement after UV irradiation (UniProt Q9NZB2: subcellular location). Routine tissue IHC has no supplied UV exposure context, so membrane enrichment is not required.
Antibody evidence	HPA019734 and HPA055800 each have Approved IHC status and Enhanced ICC status (HPA: antibody validation). Those labels support use of the reported patterns while retaining the tissue IHC caveat of medium staining–RNA consistency and pending external verification (HPA: tissue IHC reliability). ICC validation does not specify a paraffin-section dilution or retrieval condition.
Isoforms and epitope information	UniProt lists 5 FAM120A isoforms, A, B, D, E and F (UniProt Q9NZB2: isoforms). The supplied record does not locate the IHC antibody epitope or establish which isoforms it detects. Interpret a distribution mismatch against the HPA tissue pattern, without assigning it to a particular isoform.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Expected glandular cells show no stain.	The slide may lack the relevant cell population, or the IHC workflow may have failed; neither is established by an unstained section (HPA: High in specified glandular cells; general IHC practice).	Confirm cell identity on the counterstain, compare a documented positive tissue, and check the antibody, retrieval and chromogenic detection steps using their supplied instructions (general IHC practice).
Adipocytes or other unexpected cells dominate the stain.	Strong adipocyte staining conflicts with the HPA Not detected call and may reflect nonspecific binding or endogenous detection activity (HPA: adipocytes; general IHC interpretation).	Run a no-primary control and review blocking and detection conditions; require cytoplasmic staining in an HPA-positive cell population before calling the result supportive (general IHC practice; HPA: tissue IHC).
Background obscures cellular borders throughout the section.	Diffuse chromogen can arise from background binding or endogenous enzyme activity in chromogenic IHC (general IHC practice).	Use a no-primary control to locate detection background, then optimise blocking, antibody concentration and wash steps according to the assay instructions (general IHC practice). Rescore only discernible cellular cytoplasm (HPA: tissue IHC pattern).
Signal appears mainly nuclear or exclusively membranous.	A nuclear-dominant pattern disagrees with HPA's cytoplasmic observations; UniProt notes membrane translocation after UV, but no UV context is supplied for this section (HPA: tissue IHC; UniProt Q9NZB2: localisation).	Check the positive control and cellular counterstain, and repeat with the IHC-validated antibody if needed (general IHC practice). Record membrane enrichment as an observation without assuming UV-related translocation.
IF/ICC check: where should FAM120A fluorescence appear?	HPA reports a cytosolic main location in ICC-IF and Enhanced ICC validation for HPA019734 and HPA055800 (HPA: subcellular; HPA: antibody validation). These are cell-image observations, not an IHC-P protocol.	Expect predominantly cytosolic fluorescence and use appropriate fluorescence controls to assess background (HPA: subcellular; general IF practice). Interpret the paraffin-section chromogenic result against HPA tissue IHC separately.

Source: UniProt Q9NZB2 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing FAM120A staining

M09208 staining FAM120A in human brain sections by Immunohistochemistry (IHC-P -paraformaldehyde-fixed, paraffin-embedded sections). Tissue was fixed with formaldehyde and blocked with 3% BSA for 0. 5 hour at room temperature; antigen retrieval was by heat mediation with a citrate buffer (pH6). Samples were incubated with primary antibody (1/25) for 1 hours at 37°C. A undiluted biotinylated goat polyvalent antibody was used as the secondary antibody.

M09208 · IHCM09208 staining FAM120A in human brain sections by Immunohistochemistry (IHC-P -paraformaldehyde-fixed, paraffin-embedded sections). Tissue

Immunofluorescent analysis of 4% paraformaldehyde-fixed, 0.1% Triton X-100 permeabilized HeLa (human cervical epithelial adenocarcinoma cell line) cells labeling FAM120A with M09208 at 1/25 dilution, followed by Dylight® 488-conjugated goat anti-mouse IgG secondary antibody at 1/200 dilution (green). Immunofluorescence image showing cytoplasm staining on HeLa cell line. Cytoplasmic actin is detected with Dylight® 554 Phalloidin at 1/100 dilution (red).The nuclear counter stain is DAPI (blue).

M09208 · IFImmunofluorescent analysis of 4% paraformaldehyde-fixed, 0.1% Triton X-100 permeabilized HeLa (human cervical epithelial adenocarcinoma cell

A09208 · IHCImmunohistochemistry of FAM120A in rat brain tissue with FAM120A antibody at 2.5 μg/mL.

A09208 · IFImmunofluorescence of FAM120A in Rat Brain cells with FAM120A antibody at 20 μg/mL.

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000048828-FAM120A/tissue/cerebral+cortex#imid_5172612

HPA · StomachHuman Protein Atlas IHC, Stomach. Source: https://www.proteinatlas.org/ENSG00000048828-FAM120A/tissue/stomach+1#imid_5172528

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000048828-FAM120A/tissue/colon#imid_5172554

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000048828-FAM120A/tissue/liver#imid_5172555

HPA · ICC-IF A-431Human Protein Atlas immunofluorescence, A-431, antibody HPA019734; green = FAM120A, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for FAM120A IHC & IF

🧪Run appendix first: glandular cells should stain (HPA: High in appendix glandular cells). Use adipose tissue adipocytes as the negative tissue (HPA: Not detected in adipocytes); on the appendix slide, cells without signal can show local background, but the supplied HPA rows do not establish them as true negative cells.

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

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show FAM120A in A-431, U-251MG, U2OS, KOLF2.1J, with annotated localisation: Cytosol (enhanced) (HPA subcellular).

Technical controls: Include a no-primary (secondary-only) control, an isotype control matched to the primary antibody’s host species and isotype, and a biological negative such as knockout tissue or a validated peptide block. For chromogenic staining, check endogenous peroxidase and, if using the caption’s biotinylated secondary antibody, endogenous biotin background (M09208 tissue-IHC caption: biotinylated secondary).

⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the exact M09208 tissue-IHC caption’s fixative is unreported (M09208 tissue-IHC caption). Retrieval dependence is unreported; that caption describes heat-mediated citrate retrieval at pH 6 (M09208 tissue-IHC caption). The supplied evidence does not establish whether frozen sections or IF are easier; watch for endogenous biotin background when using the caption’s biotinylated detection method (M09208 tissue-IHC caption).

HPA tissue IHC evidence for FAM120A

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium consistency between antibody staining and RNA expression data. Pending external verification.). 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 →
Breast	Glandular cells	High	Protein (IHC)	HPA →
Bronchus	Respiratory epithelial cells	High	Protein (IHC)	HPA →
Caudate	Glial cells	High	Protein (IHC)	HPA →
Cerebellum	Purkinje cells	High	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Adipose tissue	Adipocytes	Not detected	Protein (IHC)	HPA →

Section 3

Advanced FAM120A IHC Tips

Troubleshoot FAM120A staining in paraffin sections by checking retrieval, cell type, subcellular pattern, and controls together.

How should I adjust retrieval when FAM120A staining is weak?

Start with heat-mediated antigen retrieval in citrate buffer at pH 6 for paraffin sections (datasheet M09208). Keep heating and cooling conditions consistent between slides, then compare a tissue with expected staining against a no-primary control; cerebral cortex neuronal cells are reported as high expressers (standard IHC practice; HPA: high in cerebral cortex neuronal cells). If staining remains weak, test a longer heating interval on adjacent sections before changing buffer, and watch for tissue lifting or diffuse background (standard IHC practice). Score any gain within the expected cytoplasmic compartment, since stronger staining alone does not establish specificity (HPA: general cytoplasmic expression; standard IHC practice).

Could fixation explain inconsistent FAM120A staining between blocks?

Target-specific sensitivity of FAM120A staining to fixative choice or fixation duration is unknown because no fixation comparison is supplied (provided evidence: no target-specific fixation comparison). Record the fixative, time before fixation, and fixation duration for each block, and compare sections processed with the same citrate retrieval at pH 6 (standard IHC practice; datasheet M09208). If staining differs, examine morphology and a same-run positive control before attributing the change to FAM120A abundance (standard IHC practice). Its reported cytoplasmic location and post-UV membrane translocation describe localisation, but do not establish how this epitope responds to fixation (UniProt Q9NZB2; standard IHC practice).

Should membrane staining count as FAM120A positive in tissue?

Expect predominantly cytoplasmic staining in routine tissue sections, consistent with the reported general cytoplasmic IHC profile and enhanced cytosolic IF location (HPA: tissue IHC profile; HPA: subcellular location). FAM120A can move from cytosol to plasma membrane after UV irradiation, so a membrane-associated pattern has biological precedent only when the experimental context supports it (UniProt Q9NZB2). It has no annotated transmembrane segment, and membrane staining should not be scored as proof of an integral membrane protein (UniProt Q9NZB2 topology; standard IHC practice). Check whether the signal follows cell boundaries rather than section edges, and compare its distribution with a no-primary control (standard IHC practice).

Can this antibody distinguish FAM120A isoforms or modification states?

The record lists five isoforms, A, B, D, E and F, but the supplied evidence does not map this antibody’s epitope to an isoform-specific region (UniProt Q9NZB2; provided evidence: epitope unmapped). Consequently, report staining as FAM120A immunoreactivity unless isoform selectivity is established independently (standard IHC practice). Annotated modifications include phosphothreonine at residue 655, methylarginines at 873, 884 and 886, and acetyllysine at 932; none establishes modification-specific recognition by this antibody (UniProt Q9NZB2; provided evidence: epitope unmapped). If a treatment changes staining, compare matched sections and an orthogonal readout before assigning the change to one isoform or modification (standard IHC practice).

How should I follow up the tissue IHC pattern with multiplex IF?

Use a cell-type marker alongside FAM120A and compare the signal within the expected population; cerebral cortex neuronal cells are reported as high in tissue IHC (HPA: high in cerebral cortex neuronal cells; standard IF practice). Choose a spectrally separated, preferably far-red fluorophore where tissue autofluorescence is troublesome, and include single-label and no-primary controls (standard IF practice). Cytosolic localisation is supported by IF images, while membrane association after UV exposure is reported separately (HPA: enhanced cytosolic location; UniProt Q9NZB2). For an intracellular epitope, optimise permeabilisation; for a proposed membrane-facing epitope, establish its accessible side experimentally because the supplied record gives no antibody epitope orientation (standard IF practice; provided evidence: epitope orientation unreported).

What should I check when the DAB signal is widespread?

First compare no-primary and secondary-only controls, since staining present there indicates a detection-system contribution rather than convincing FAM120A localisation (standard IHC practice). The selected IHC caption used 3% BSA for 0.5 hour and a biotinylated secondary, so review blocking consistency and assess endogenous biotin if that detection scheme is used (caption M09208; standard IHC practice). Include a peroxidase block before DAB development and keep development time matched across sections; these are general chromogenic workflow steps (standard IHC practice). Retain signal as plausible only when it resolves into cells and the expected cytoplasmic distribution, rather than diffuse staining across the section (HPA: general cytoplasmic expression; standard IHC practice).

How can I compare FAM120A IHC across samples fairly? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and cytoplasmic compartment before scoring, because tissue IHC reports general cytoplasmic expression and different cell types can have different staining levels (HPA: tissue IHC profile; standard IHC practice). For intensity and prevalence, use an H-score from 0 to 300 or report the percentage of positive cells using a fixed threshold (standard IHC practice). If spatial distribution matters, report positive-cell density per mm² of evaluable tissue and exclude folds or necrotic areas consistently (standard IHC practice). Normalise comparisons to the same cell type and evaluable area, with matched retrieval, detection and a same-run control section (standard IHC practice).

How do I separate true FAM120A staining from tissue artefact?

A credible positive pattern is cellular and mainly cytoplasmic, with signal in an expected population such as cerebral cortex neuronal cells or cerebellar Purkinje cells (HPA: general cytoplasmic expression; HPA: high in those cells). Treat staining restricted to section edges, folds or necrotic regions as suspect, and compare those areas with intact tissue on the same slide (standard IHC practice). Check a no-primary control for endogenous enzyme or detection background before calling diffuse DAB deposition positive (standard IHC practice). The reported absence in adipocytes can provide a contextual comparison, but the tissue profile has only medium RNA-staining consistency and awaits external verification (HPA: adipocytes not detected; HPA: reliability description).

Boster reagents

Best FAM120A / Constitutive coactivator of PPAR-gamma-like protein 1 IHC Antibodies

Anti-FAM120A antibodies have IHC images from human and rat brain tissue and IF images from human HeLa and rat brain cells (catalog image captions). Listed reactivity spans human, mouse, and rat (catalog reactivity).

Real IHC data

Anti-FAM120A Antibody

Cat # M09208

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Real IHC data Immunohistochemistry of FAM120A in rat brain tissue with FAM120A antibody at 2.5 μg/mL.

Anti-FAM120A Antibody

Cat # A09208

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M09208 has an IHC-P image of formaldehyde-fixed, paraffin-embedded human brain and an IF image of HeLa cells (M09208 image captions). A09208 has an IHC image of rat brain tissue and an IF image of rat brain cells; its IHC caption does not report the fixative (A09208 image captions).

Which to pick: For human paraffin-section IHC, choose the mouse monoclonal M09208: its IHC caption documents that preparation, and IHC-P is listed as an application (M09208 catalog entry and IHC image caption). For IF/ICC, choose M09208 for human HeLa cells or A09208 for rat brain cells, matching their respective IF images (M09208 and A09208 IF image captions). For work across species, consider A09208, a rabbit antibody with human, mouse, and rat listed as reactive; its IHC image shows rat brain tissue, but the caption does not report fixation or paraffin processing (A09208 catalog entry and IHC image caption).

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

References

UniProt Consortium. UniProt entry Q9NZB2 (F120A_HUMAN, Constitutive coactivator of PPAR-gamma-like protein 1).
Human Protein Atlas. FAM120A tissue IHC expression (reliability: Approved).
Human Protein Atlas. FAM120A subcellular location (ICC-IF): Localized to the cytosol..
Human Protein Atlas. FAM120A antibody validation summary (2 antibodies).
Functional characterization of FAM120A as a novel effector in the progranulin/EphA2 oncogenic axis in bladder cancer. Journal of experimental & clinical cancer research : CR 2026 — PMC13602547.
FAM120A deficiency improves resistance to cisplatin in gastric cancer by promoting ferroptosis. Communications biology 2024 — PMC10987584.
PubMed PMID:15164053 — UniProt-cited evidence.
PubMed PMID:15489334 — UniProt-cited evidence.
PubMed PMID:8724849 — UniProt-cited evidence.