MAT2A / S-adenosylmethionine synthase isoform type-2 · IHC design guide

Design Immunohistochemistry for MAT2A

Plan MAT2A chromogenic IHC in paraffin sections using the catalog antibody's 2–5 μg/ml range (datasheet A04557-1). Assess nuclear and cytoplasmic staining, and validate the pattern because antibody staining and RNA show low consistency (HPA tissue IHC).

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

Immunohistochemistry protocol sheet for MAT2A (IHC for MAT2A): expected localisation Nuclear and cytoplasmic in several tissues (HPA tissue IHC), antibody A04557-1, validated IHC image, and IHC protocol steps — Printable **MAT2A** IHC protocol sheet — expected localisation Nuclear and cytoplasmic in several tissues (HPA tissue IHC), antibody A04557-1, controls and protocol steps. Open the full MAT2A IHC guide →

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MAT2A 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 and cytoplasmic in several tissues (HPA tissue IHC)
	Staining pattern	Several cell types show nuclear and cytoplasmic staining (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A04557-1)
	Positive control ⓘ	Bone marrow+4 more · see all
	Negative control ⓘ	Adipose tissue+4 more · see all

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 and RNA show low consistency; validate the pattern (HPA tissue IHC)
	Regulation	Expression regulation unreported (UniProt)
	Isoform / epitope	2 isoforms; epitope coverage needs validation (UniProt)

Section 1

Recommended MAT2A IHC & IF Protocols

The catalog antibody protocol uses EDTA retrieval (datasheet A04557-1). Two published MAT2A IHC protocols provide additional conditions for kidney and liver tissue (PMC4003826; PMC3089560).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human rectal cancer tissue; fixative not specified (datasheet A04557-1)
Fixation	Image fixative and duration unreported (datasheet A04557-1); 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 A04557-1); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A04557-1)
Primary antibody	Rabbit anti-MAT2A, 2-5 μg/ml (datasheet A04557-1)
Primary incubation	Overnight at 4 °C (datasheet A04557-1)
Detection	HRP-conjugated secondary, DAB chromogen (datasheet A04557-1)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	MAT2A-positive staining in hematopoietic cells of bone marrow (HPA tissue IHC: Medium). HPA tissue profile: Nuclear and cytoplasmic expression in several tissues. No signal in the no-primary control.

💡Decision noteStart with heat-mediated EDTA at pH 8.0 for the catalog antibody (datasheet A04557-1); the published protocols used citrate retrieval (PMC4003826; PMC3089560).

Section 2

What Is the Expected MAT2A Staining Pattern?

MAT2A staining in paraffin sections is reported in nuclei and cytoplasm across several tissues (HPA tissue IHC). Expect cell-specific staining, including medium staining in bone marrow hematopoietic cells and bronchial respiratory epithelial cells (HPA tissue IHC). MAT2A has no annotated transmembrane segment (UniProt P31153 topology). Treat the tissue pattern as provisional: HPA rates it Approved but reports low consistency with RNA data and pending external verification (HPA tissue IHC).

What am I looking at on my slide?
Nuclear and cytoplasmic signal appears in hematopoietic cells in bone marrow or respiratory epithelial cells in bronchus (HPA tissue IHC).	This fits the reported compartments and medium staining in those specific cells (HPA tissue IHC). Judge the named cells, since a whole-tissue label does not establish uniform staining across every cell.
Signal is restricted to cell outlines, extracellular material, or a sharply membrane-bound pattern.	That distribution conflicts with the reported nuclear and cytoplasmic IHC profile (HPA tissue IHC) and the absence of a transmembrane segment (UniProt P31153 topology). Investigate an artefact before calling it MAT2A.
Strong staining appears in adipocytes or cardiomyocytes, while the intended positive cells are absent.	HPA reports MAT2A as not detected in those cell types (HPA tissue IHC). Consider antibody cross-reactivity or endogenous chromogenic activity; check omission controls and the cell-specific reference pattern (general IHC practice).
Color spreads across tissue and blank spaces, obscuring cell boundaries.	Diffuse signal cannot establish the reported nuclear and cytoplasmic distribution (HPA tissue IHC). Check blocking, wash stringency, antibody concentration, and detection-only controls as general IHC practice.
No signal appears in bone marrow hematopoietic cells or bronchial respiratory epithelial cells.	Both are reported at medium intensity (HPA tissue IHC), so inspect tissue preservation, retrieval, primary antibody application, and detection controls (general IHC practice). HPA’s low RNA–staining consistency limits certainty about any single specimen (HPA tissue IHC).

💡Expected MAT2A appearanceCall a result positive when identifiable bone marrow hematopoietic cells or bronchial respiratory epithelial cells show nuclear and cytoplasmic staining at roughly medium intensity (HPA tissue IHC); isolated membrane or diffuse tissue-wide color warrants control checks (general IHC practice).

How each factor affects the staining
Cell and tissue selection	Use HPA’s cell-level calls: bone marrow hematopoietic cells and bronchial respiratory epithelial cells are Medium, whereas adipocytes and cardiomyocytes are Not detected (HPA tissue IHC). These are comparison patterns, not universal guarantees.
Compartment and topology	HPA reports nuclear and cytoplasmic tissue staining (HPA tissue IHC); UniProt annotates no transmembrane segment (UniProt P31153 topology). Prioritize intracellular, cell-resolved signal when interpreting chromogenic sections.
IF/ICC expectation?	The separate IF/ICC evidence places MAT2A mainly in nucleoplasm, with additional cytosol localization (HPA subcellular ICC-IF). This supports a compartment comparison; the reported tissue IHC profile remains the reference for this guide (HPA tissue IHC).
Isoforms and epitope coverage	UniProt lists 2 isoforms (UniProt P31153). The supplied records do not map antibody epitopes to either isoform, so staining cannot identify an isoform without additional validation.
Evidence strength	HPA lists HPA043028 and CAB009968 as IHC Approved, yet reports low consistency with RNA expression and pending external verification (HPA antibodies; HPA tissue IHC). Approval alone does not establish the stronger Enhanced validation designation.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Positive-control cells are blank despite a clean counterstain.	Retrieval, primary antibody application, or chromogenic detection may have failed (general IHC practice); HPA reports medium staining in bone marrow hematopoietic cells and bronchial respiratory epithelial cells (HPA tissue IHC).	Check the control cells on the slide, confirm each incubation and reagent, then review retrieval and detection against the antibody’s validated IHC conditions (general IHC practice).
Nuclei stain, but cytoplasm does not.	The balance of compartments can vary across a section; HPA reports both nuclear and cytoplasmic tissue expression without requiring equal intensity in every cell (HPA tissue IHC).	Score nuclear and cytoplasmic compartments separately in identifiable cells. Compare the result with a suitable positive control before treating absent cytoplasmic color as assay failure (general IHC practice).
Only membranes or extracellular deposits are prominent.	This disagrees with the reported intracellular IHC pattern (HPA tissue IHC) and the lack of a transmembrane segment (UniProt P31153 topology); precipitated chromogen or nonspecific staining is possible (general IHC practice).	Inspect morphology and a detection-only control, then reassess washing and chromogen development (general IHC practice). Do not score deposits as MAT2A-positive cells.
Adipocytes or cardiomyocytes stain strongly.	Those specific cell types are listed as Not detected (HPA tissue IHC). Antibody cross-reactivity or endogenous detection activity may explain unexpected color (general IHC practice).	Run a primary-omission control and inspect the detection chemistry; compare staining with a reported positive cell population (general IHC practice; HPA tissue IHC).
Nearly every cell and open area develops faint color.	Background from incomplete blocking, excessive antibody or detection reagent, or insufficient washing can hide cell-specific localization (general IHC practice).	Check omission controls and adjust blocking, washing, or reagent concentration within the validated IHC workflow (general IHC practice). Interpret only clearly bounded cellular signal.
A reported positive population varies between specimens.	HPA’s tissue calls are observational, and its IHC summary reports low consistency with RNA data and pending external verification (HPA tissue IHC). A single discrepancy does not establish biological absence.	Compare the same named cell type across sections, document compartment and intensity, and repeat with an appropriate positive control or independent validation when the conclusion depends on the discrepancy (general IHC practice).

Source: UniProt P31153 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing MAT2A staining

IHC analysis of MAT2A using anti-MAT2A antibody (A04557-1). MAT2A was detected in a paraffin-embedded section of human rectal 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 2 μg/ml rabbit anti-MAT2A Antibody (A04557-1) 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.

A04557-1 · IHCIHC analysis of MAT2A using anti-MAT2A antibody (A04557-1). MAT2A was detected in a paraffin-embedded section of human rectal cancer tissue.

IHC analysis of MAT2A using anti-MAT2A antibody (A04557-1). MAT2A 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 2 μg/ml rabbit anti-MAT2A Antibody (A04557-1) 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.

A04557-1 · IHCIHC analysis of MAT2A using anti-MAT2A antibody (A04557-1). MAT2A was detected in a paraffin-embedded section of human tonsil tissue. Heat m

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000168906-MAT2A/tissue/cerebral+cortex#imid_12291753

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000168906-MAT2A/tissue/colon#imid_12291663

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000168906-MAT2A/tissue/liver#imid_12291672

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000168906-MAT2A/tissue/kidney#imid_12291665

HPA · ICC-IF PC-3Human Protein Atlas immunofluorescence, PC-3, antibody HPA043028; green = MAT2A, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for MAT2A IHC & IF

🧪Run breast first: glandular cells should stain at a Medium level (HPA: breast glandular cells, Medium). Use adipose tissue as the negative tissue: adipocytes are Not detected (HPA: adipose tissue adipocytes, Not detected); if adipocytes are present beside the breast glands, they should show only background signal as an internal negative reference (HPA: adipose tissue adipocytes, Not detected).

Positive control tissue: Bone marrow (Hematopoietic cells, HPA Medium)

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show MAT2A in PC-3, U-251MG, U2OS, HAP1, HeLa, KOLF2.1J, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).

Technical controls: Include a no-primary, secondary-only control and a concentration-matched rabbit IgG isotype control (selected A04557-1 caption: rabbit primary; standard IHC practice). A MAT2A-knockout specimen processed alongside the positive slide provides a biological negative; quench endogenous peroxidase in blood-containing breast sections before HRP/DAB detection (standard IHC practice; selected A04557-1 caption: HRP/DAB).

⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence, and the fixative in the selected A04557-1 paraffin-section caption is unreported (selected A04557-1 caption). That example uses heat-mediated EDTA retrieval at pH 8.0; it provides a starting condition but does not establish that retrieval is required for every specimen (selected A04557-1 caption). ICC-IF images support MAT2A detection in cultured cells, but the supplied evidence does not establish whether IF or frozen sections are easier; score breast glandular cells specifically so adipose spaces are not mistaken for glandular negatives (HPA: MAT2A subcellular ICC-IF images; HPA: breast glandular cells, Medium; standard histology practice).

HPA tissue IHC evidence for MAT2A

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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
Bone marrow	Hematopoietic cells	Medium	Protein (IHC)	HPA →
Breast	Glandular cells	Medium	Protein (IHC)	HPA →
Bronchus	Respiratory epithelial cells	Medium	Protein (IHC)	HPA →
Cerebellum	Purkinje cells	Medium	Protein (IHC)	HPA →
Cervix	Squamous epithelial cells	Medium	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Adipose tissue	Adipocytes	Not detected	Protein (IHC)	HPA →
Appendix	Glandular cells	Not detected	Protein (IHC)	HPA →
Caudate	Glial cells	Not detected	Protein (IHC)	HPA →
Duodenum	Glandular cells	Not detected	Protein (IHC)	HPA →
Heart muscle	Cardiomyocytes	Not detected	Protein (IHC)	HPA →

Section 3

Advanced MAT2A IHC Tips

Troubleshoot MAT2A chromogenic IHC in paraffin sections by checking retrieval, controls, compartment, and cell type before interpreting staining intensity.

How should I adjust retrieval when MAT2A staining is weak or tissue morphology deteriorates?

Start with heat-mediated retrieval in EDTA at pH 8.0 for paraffin sections stained with A04557-1 (datasheet A04557-1). If staining is weak, compare heating times on matched sections while holding buffer, pH, antibody concentration, and detection constant (standard IHC practice). The illustrated workflow uses 10% goat serum and 2 μg/ml primary antibody overnight at 4°C after retrieval (datasheet A04557-1). If morphology deteriorates or staining concentrates at section edges, reduce retrieval intensity and inspect controls before increasing primary antibody (standard IHC practice). Interpret modest changes cautiously because tissue staining has low agreement with RNA data and awaits external verification (HPA tissue IHC).

Can the MAT2A tissue image establish an optimal fixative or fixation time?

No fixative or fixation duration is reported for the pictured paraffin section, so MAT2A-specific fixation sensitivity remains unknown (datasheet A04557-1). Record the fixative and processing history for each specimen, and compare matched sections when investigating weak staining (standard IHC practice). Keep retrieval at EDTA pH 8.0 and primary antibody at 2 μg/ml initially so processing differences remain interpretable (datasheet A04557-1; standard IHC practice). Examine preserved morphology alongside signal; excessive tissue damage can make an apparent gain in DAB intensity misleading (standard IHC practice). Neither reported protein modifications nor tissue staining patterns establish a fixation effect for this antibody (UniProt P31153; HPA tissue IHC).

How should I assess nuclear and cytoplasmic MAT2A staining in paraffin sections?

Evaluate nuclei and cytoplasm separately because tissue IHC reports both compartments, while cell imaging places MAT2A mainly in nucleoplasm with additional cytosol (HPA tissue IHC; HPA subcellular). Use a nuclear counterstain to identify the compartment and score DAB only where cellular boundaries remain clear (standard IHC practice). MAT2A has no annotated transmembrane segment or signal peptide, so a crisp membrane-only pattern warrants scrutiny (UniProt P31153 topology and processing). Compare cellular patterns across intact central tissue and section edges to identify uneven staining (standard IHC practice). Nuclear signal alone does not establish specificity: compare matched controls and the expected cell population before assigning it to MAT2A (HPA tissue IHC; standard IHC practice).

Can this antibody distinguish MAT2A isoforms or modified epitopes in tissue?

MAT2A has 2 reported isoforms, but the supplied IHC caption does not map the antibody epitope or establish isoform discrimination (UniProt P31153; datasheet A04557-1). The protein also has reported modified residues at positions 81, 114, and 384; their effects on this antibody are untested here (UniProt P31153). Treat DAB signal as antibody-reactive MAT2A staining rather than an isoform-specific or modification-specific readout (UniProt P31153; datasheet A04557-1). If an isoform claim matters, obtain epitope mapping and validate against an independent isoform-sensitive assay before interpreting regional staining (standard IHC practice). Keep staining and scoring conditions matched across sections because intensity differences alone cannot identify which epitope was detected (standard IHC practice).

How can follow-up IF help resolve an ambiguous MAT2A IHC pattern?

Use the IHC result to select regions for follow-up IF, while treating the 2 μg/ml overnight primary condition as evidence for the pictured paraffin IHC workflow only (datasheet A04557-1). Multiplex MAT2A with a marker for the cell population being assessed so colocalisation can distinguish cell identity from neighboring staining (standard IF practice). Choose fluorophores after inspecting tissue autofluorescence and include single-channel controls for bleed-through (standard IF practice). Assess nuclear and cytosolic signal separately because both are reported MAT2A locations (HPA subcellular). Since MAT2A lacks a transmembrane segment and is reported inside cells, choose permeabilisation for access to intracellular epitopes, then validate it in IF (UniProt P31153 topology; HPA subcellular; standard IF practice).

What should I check when DAB obscures MAT2A staining?

Run a primary-omission control to assess secondary reagent and detection background in the same paraffin tissue (standard IHC practice). Block endogenous peroxidase before HRP/DAB detection, and compare pigment or precipitate in the control with the test section (standard IHC practice). The pictured MAT2A workflow uses peroxidase-conjugated anti-rabbit secondary for 30 minutes at 37°C, followed by DAB development (datasheet A04557-1). If diffuse staining persists, compare shorter development or lower primary concentration on matched sections, changing one condition at a time (standard IHC practice). Do not treat every stained cell as positive: HPA reports cell-type differences across tissues and low agreement with RNA data (HPA tissue IHC).

How should I quantify MAT2A IHC across heterogeneous tissue regions? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and tissue region before scoring, then report nuclear and cytoplasmic staining separately (HPA tissue IHC; standard IHC practice). Within each defined population, record percent positive cells and staining intensity for an H-score, or count positive cells per mm² when cell density is the outcome (standard IHC practice). Normalise counts to evaluable tissue area and intensity scores to the same cell type across matched sections (standard IHC practice). Exclude folds, necrotic regions, and damaged edges using prespecified criteria, and retain the underlying cell counts for review (standard IHC practice). Interpret small differences cautiously because the HPA tissue IHC profile has low agreement with RNA expression data (HPA tissue IHC).

Which findings support genuine MAT2A staining rather than an IHC artefact?

Look for reproducible cellular nuclear or cytoplasmic staining with preserved morphology, consistent with reported MAT2A tissue and subcellular patterns (HPA tissue IHC; HPA subcellular). Question staining restricted to membranes because MAT2A has no annotated transmembrane segment or signal peptide (UniProt P31153 topology and processing). Compare the stained cell type with the annotated tissue profile; for example, HPA reports medium signal in breast glandular cells but no detectable signal in adipocytes (HPA tissue IHC). Discount edge-only signal, necrotic deposits, and DAB present in primary-omission controls after checking endogenous peroxidase blocking (standard IHC practice). Require independent corroboration for a strong biological claim because the HPA tissue IHC profile has low agreement with RNA data and awaits external verification (HPA tissue IHC).

Boster reagents

Best MAT2A / S-adenosylmethionine synthase isoform type-2 IHC Antibodies

A04557-1 has IHC images from human paraffin sections (catalog image captions); M04557 is listed for ICC/IF in human, mouse and rat, without an IF image (catalog applications, reactivity and image alts).

Real IHC data

Anti-MAT2A Antibody ®

Cat # A04557-1

View product →

A04557-1 is listed for IHC and has images from human paraffin sections, including rectal cancer and tonsil; its listed reactivity is human, mouse and rat (catalog applications, image captions and reactivity). M04557 is listed for ICC/IF in human, mouse and rat, but has no IF image in the payload (catalog applications, reactivity and image alts).

Which to pick: Choose A04557-1 for tissue IHC: its own images document human paraffin sections, with 2 μg/ml primary antibody in the captions; the fixative is unreported (A04557-1 image captions). Choose rabbit monoclonal M04557 for ICC/IF based on its listed application and clone 25M89, while treating IF performance as undocumented by an image here (M04557 catalog applications, clone and image alts). Both list human, mouse and rat reactivity, but the supplied tissue IHC images demonstrate human samples only (catalog reactivity; A04557-1 image captions).

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

References

UniProt Consortium. UniProt entry P31153 (METK2_HUMAN, S-adenosylmethionine synthase isoform type-2).
Human Protein Atlas. MAT2A tissue IHC expression (reliability: Approved).
Human Protein Atlas. MAT2A subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cytosol..
Human Protein Atlas. MAT2A antibody validation summary (3 antibodies).
Expression of methionine adenosyltransferase 2A in renal cell carcinomas and potential mechanism for kidney carcinogenesis. BMC cancer 2014 — PMC4003826.
SYVN1-MTR4-MAT2A Signaling Axis Regulates Methionine Metabolism in Glioma Cells. Frontiers in cell and developmental biology 2021 — PMC8042234.
Translocation of Methionine Adenosyl Transferase MAT2A and Its Prognostic Relevance for Liver Hepatocellular Carcinoma. International journal of molecular sciences 2023 — PMC10218821.
The X protein of hepatitis B virus inhibits apoptosis in hepatoma cells through enhancing the methionine adenosyltransferase 2A gene expression and reducing S-adenosylmethionine production. The Journal of biological chemistry 2011 — PMC3089560.
PubMed PMID:1426236 — UniProt-cited evidence.
PubMed PMID:16413417 — UniProt-cited evidence.
PubMed PMID:14702039 — UniProt-cited evidence.