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MGAM / Maltase-glucoamylase · IHC design guide
Design Immunohistochemistry for MGAM
Plan MGAM chromogenic IHC in paraffin sections around apical microvillar staining in small intestine and kidney, with cytoplasmic staining in subsets of leukocytes (HPA tissue IHC). This guide covers fixation, controls and scoring for those patterns.
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
MGAM 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 | Apical microvilli; leukocyte cytoplasm (HPA tissue IHC) | |
| Staining pattern | Membranous in intestinal and kidney microvilli; cytoplasmic in some leukocytes (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A07347) | |
| Positive control | Duodenum+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 paraffin sections. (standard IHC practice; not target-specific) | |
| Caveat | Presumed off-target staining was observed and disregarded (HPA tissue IHC) | |
| Regulation | High expression in small intestine (UniProt) | |
| Isoform / epitope | 2 isoforms; check epitopes against cytoplasmic 1–13 and luminal 35–2753 regions (UniProt) |
Section 1
Recommended MGAM IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by published MGAM protocols for duodenal tissue (PMC3520432) and colonic biopsies (PMC8155054).
| Sample | Paraffin-embedded rat colon tissue; fixative not specified (datasheet A07347) |
| Fixation | Image fixative and duration unreported (datasheet A07347); 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 A07347); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A07347) |
| Primary antibody | Rabbit anti-MGAM, 2-5 μg/ml (datasheet A07347) |
| Primary incubation | Overnight at 4 °C (datasheet A07347) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A07347) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | MGAM-positive staining in enterocytes - Microvilli of duodenum (HPA tissue IHC: High). HPA tissue profile: Distinct membranous expression in small intestine and kidney as well as cytoplasmic expression in subsets of leukocytes. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet A07347); citrate pH 6.0 is a published alternative (PMC3520432).
Section 2
What Is the Expected MGAM Staining Pattern?
MGAM is an apical brush-border membrane protein with residues 35–2753 on the lumenal side (UniProt O43451 topology). In IHC, expect strong microvillar staining in small-intestinal and duodenal enterocytes and kidney proximal tubules (HPA: High). HPA also reports high staining in epididymal glandular cells and cytoplasmic staining in subsets of leukocytes (HPA: tissue IHC). Its tissue IHC reliability is Enhanced, although presumed off-target binding was observed and disregarded (HPA: reliability).
| A crisp apical rim lines intestinal enterocytes or kidney proximal tubules. | This matches the high microvillar staining reported in both sites (HPA: High in enterocyte and proximal-tubule microvilli) and MGAM's brush-border location (UniProt O43451 subcellular location). Judge the rim against cell boundaries, rather than overall brown intensity. |
| Enterocytes show predominantly nuclear, basal, or uniform cytoplasmic staining without an apical rim. | That distribution does not match the expected enterocyte pattern (HPA: distinct membranous expression in small intestine; UniProt O43451: apical brush border). Treat it as a localisation discrepancy and review morphology and staining controls before calling it MGAM. |
| Strong staining appears in an unexpected cell population. | Check the cell identity before calling it cross-reactivity: HPA reports cytoplasmic staining in subsets of leukocytes and high staining in epididymal glandular cells (HPA: tissue IHC). Staining confined to adipocytes, adrenal glandular cells, or bronchial respiratory epithelium conflicts with their reported 'Not detected' results (HPA: tissue IHC). |
| Brown signal spreads across stroma, lumina, and unrelated cells. | A diffuse pattern obscures the compartment needed for interpretation (HPA: distinct membranous expression in small intestine and kidney). In chromogenic IHC, nonspecific detection or endogenous enzyme activity can contribute to background (general IHC practice); compare detection controls before assigning target staining. |
| No apical signal appears in an intact small-intestinal positive control. | This disagrees with high enterocyte-microvillar staining (HPA: High in small intestine and duodenum). Check tissue preservation and section orientation, then the antibody, retrieval, and detection steps (general IHC practice). One failed section does not establish absent MGAM expression. |
💡Expected MGAM appearanceCall a convincing positive a strong, crisp apical microvillar rim in intestinal enterocytes or kidney proximal tubules (HPA: High; UniProt O43451: brush border); diffuse or misplaced staining alone is unconvincing.
| Which compartment should anchor scoring? | MGAM has one transmembrane segment at residues 14–34 and a lumenal region at 35–2753 (UniProt O43451 topology). Score epithelial apical staining in its tissue context (HPA: enterocyte and proximal-tubule microvilli). |
| How broad is the positive-tissue range? | HPA reports High staining in duodenum, small intestine, kidney, and epididymis; Medium in bone marrow, parathyroid gland, and splenic red-pulp cells (HPA: tissue IHC). The reported compartment and cell population differ by site, so use a site-specific expectation. |
| How strong is the IHC pattern evidence? | The tissue profile has Enhanced reliability and reports presumed off-target binding that was disregarded (HPA: reliability). HPA002270 has Enhanced IHC validation (HPA: antibody record). These ratings support the reported pattern but do not validate every stain in a new specimen. |
| Can sequence features predict retrieval conditions? | UniProt lists 20 glycosylation sites and two isoforms (UniProt O43451). Neither record identifies the catalog antibody's epitope or a suitable antigen-retrieval condition; select retrieval from the antibody's validated IHC-P instructions, then assess the positive control (general IHC practice). |
| Q: Does this establish an IF/ICC staining pattern? | A: HPA summarises MGAM as Membrane but provides no main location or cell-line ICC-IF images (HPA: subcellular record); HPA002270 has no ICC validation listed (HPA: antibody record). The IHC tissue pattern cannot by itself validate an IF/ICC result. |
| Situation | Likely cause | Next action |
|---|---|---|
| The small-intestinal positive control has no apical staining. | The result conflicts with High enterocyte-microvillar staining (HPA: small intestine). Tissue orientation or an IHC detection step may be limiting interpretation (general IHC practice). | Confirm that intact enterocyte apices are present; check the IHC-validated antibody's instructions, retrieval, primary-antibody step, and detection controls (general IHC practice). |
| Kidney tubules stain, but no microvillar rim is discernible. | HPA reports High staining in proximal-tubule microvilli (HPA: kidney); a broad tubular signal cannot resolve that location. | Identify proximal tubules morphologically and inspect the luminal edge at suitable magnification; reduce chromogen development if the signal is saturated (general IHC practice). |
| Most of the section has diffuse brown background. | Background can arise from nonspecific antibody or detection binding, or endogenous enzyme activity in chromogenic IHC (general IHC practice). It is not the distinct membranous pattern reported for intestine and kidney (HPA: tissue IHC). | Review the no-primary and detection controls; optimise blocking, washes, antibody concentration, and endogenous-enzyme blocking as appropriate (general IHC practice). |
| Enterocytes stain mainly in the nucleus or basal cytoplasm. | That compartment conflicts with MGAM's apical brush-border assignment (UniProt O43451) and HPA's enterocyte-microvillar staining (HPA: High). | Recheck cell boundaries and the apical surface; compare a known-positive section and staining controls before scoring the displaced signal as MGAM (general IHC practice). |
| Unexpected cells stain in a nominally negative tissue. | HPA's 'Not detected' calls apply to specified cell types, including adipocytes and bronchial respiratory epithelium, rather than every cell in those tissues (HPA: tissue IHC). | Identify the stained cells first; if staining remains in a reported negative population, assess no-primary controls and antibody specificity before interpreting it (general IHC practice). |
| Cytoplasmic leukocyte staining accompanies epithelial staining. | HPA reports cytoplasmic MGAM staining in subsets of leukocytes, while UniProt reports expression in granulocytes (HPA: tissue IHC; UniProt O43451: tissue specificity). These sources do not identify every stained leukocyte subtype. | Score leukocytes separately from epithelial apical staining and confirm their identity morphologically; do not treat their cytoplasmic signal alone as proof of epithelial mislocalisation (HPA: tissue IHC). |
Experiment evidence
IHC & IF images showing MGAM staining
A07347 · IHCIHC analysis of MGAM using anti-MGAM antibody (A16132-1). MGAM was detected in a paraffin-embedded section of rat colon tissue. Heat mediate
A07347 · IHCIHC analysis of MGAM using anti-MGAM antibody (A16132-1). MGAM was detected in a paraffin-embedded section of mouse colon tissue. Heat media
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000257335-MGAM/tissue/cerebral+cortex#imid_1021628
HPA · Small intestineHuman Protein Atlas IHC, Small intestine. Source: https://www.proteinatlas.org/ENSG00000257335-MGAM/tissue/small+intestine#imid_1021537
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000257335-MGAM/tissue/colon#imid_1021562
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000257335-MGAM/tissue/liver#imid_1021547
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for MGAM IHC & IF
🧪Run duodenum first: enterocyte microvilli should show strong apical staining (HPA: High in duodenum enterocyte microvilli; UniProt O43451: brush-border localisation). Use adipose tissue adipocytes as the negative tissue (HPA: Not detected in adipocytes); adjacent non-enterocyte cells on the duodenal slide should show little or no staining relative to the brush border (HPA: High signal assigned to enterocyte microvilli).
Positive control tissue: Duodenum (Enterocytes - Microvilli, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for MGAM; derive a cell-line control from the positive tissue's cell type (Enterocytes - Microvilli) and confirm it by RNA or western blot first.
Technical controls: Include a no-primary, secondary-only control and rabbit IgG matched to the primary antibody’s isotype and clonality; a validated MGAM knockout sample is a biological specificity control (caption: rabbit primary; standard IHC practice). For chromogenic detection, quench endogenous peroxidase and inspect duodenal luminal material for nonspecific DAB deposit (caption: HRP/DAB detection; standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected paraffin-section caption does not state the fixative (selected tissue-IHC caption: fixative not stated). Heat retrieval in EDTA at pH 8.0 was used for the reported paraffin-section staining, but a retrieval dependency has not been established (selected tissue-IHC caption: EDTA heat retrieval). There is no supplied matched frozen-section or IF protocol to establish that either is easier; assess duodenal brush-border signal against luminal debris and neighboring cells when scoring (supplied evidence: IHC caption only; HPA: High in enterocyte microvilli).
HPA tissue IHC evidence for MGAM
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High consistency between antibody staining and RNA expression data. Presumed off target binding observed and disregarded.). 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 |
|---|---|---|---|---|
| Duodenum | Enterocytes - Microvilli | High | Protein (IHC) | HPA → |
| Epididymis | Glandular cells | High | Protein (IHC) | HPA → |
| Kidney | Proximal tubules (microvilli) | High | Protein (IHC) | HPA → |
| Small intestine | Enterocytes - Microvilli | High | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Endocrine cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced MGAM IHC Tips
Troubleshoot MGAM chromogenic IHC by checking retrieval, apical localisation, staining controls and compartment-specific scoring (UniProt O43451; HPA tissue IHC).
What should I change if MGAM staining is weak after antigen retrieval?
Start with heat-mediated antigen retrieval in EDTA at pH 8.0 for paraffin-section chromogenic IHC (datasheet A07347). Compare retrieval times under the laboratory’s established heater conditions while keeping section thickness and detection chemistry constant; excessive heating can damage morphology (standard IHC practice). Use small-intestinal enterocyte microvilli as a positive reference, assessing the apical border rather than total DAB alone (HPA: high in enterocyte microvilli; UniProt O43451: brush border). If staining remains weak, test another buffer only as a documented fallback alongside the EDTA condition and a no-primary control (standard IHC practice).
Can fixation explain weak MGAM staining in paraffin sections?
MGAM-specific sensitivity to fixative type or fixation duration is unknown from the supplied evidence; the paraffin-section caption does not state a fixative (caption A16132-1). Record the actual fixative and time in hours for each block before comparing staining across samples (standard IHC practice). On adjacent sections, hold retrieval at EDTA pH 8.0 and keep antibody incubation and DAB development consistent, so processing differences remain interpretable (datasheet A07347; standard IHC practice). Review tissue preservation and apical-border morphology before treating weak signal as reduced expression (UniProt O43451: brush border; standard IHC practice).
Where should convincing MGAM signal appear in tissue sections?
In small intestine, prioritise an apical microvillar pattern in enterocytes when judging chromogenic staining (UniProt O43451: apical brush-border membrane; HPA: high in enterocyte microvilli). Kidney proximal-tubule microvilli provide another reported membranous pattern, while subsets of leukocytes can show cytoplasmic staining (HPA tissue IHC). Compare the DAB signal with epithelial polarity on the counterstained section, especially where folds obscure the luminal edge (standard IHC practice). Do not require every positive cell to show the same compartment: score epithelial apical staining and leukocyte cytoplasmic staining separately, with a no-primary section to assess deposit (HPA tissue IHC; standard IHC practice).
Could epitope position or processing change the MGAM IHC pattern?
MGAM has a cytoplasmic segment at residues 1–13, a membrane segment at 14–34, and a lumenal region at 35–2753 (UniProt O43451 topology). Its record lists 2 isoforms and 20 glycosylation sites, but the supplied antibody evidence does not locate its epitope (UniProt O43451; supplied antibody evidence). Check the antibody’s documented immunogen before attributing discordant staining to an isoform or to glycan masking (standard IHC practice). Compare serial sections under the same EDTA pH 8.0 retrieval and detection conditions, then assess whether any change preserves the expected apical pattern (datasheet A07347; UniProt O43451: brush border; standard IHC practice).
How should I assess MGAM localisation in a separate multiplex IF experiment?
On the separate IF/ICC guide, pair MGAM with a marker that identifies the expected enterocytes and inspect whether MGAM follows their apical surface (HPA: high in enterocyte microvilli; UniProt O43451: brush border). Include single-colour and unstained controls, and choose spectrally separated fluorophores after checking tissue autofluorescence; a far-red channel may improve contrast (standard IF practice). Set permeabilisation according to the documented epitope: access to residues 1–13 requires intracellular access, whereas residues 35–2753 face the lumen (UniProt O43451 topology; standard IF practice). The supplied antibody evidence does not identify its epitope, so record the permeabilisation condition and verify localisation empirically (supplied antibody evidence; standard IF practice).
How can I reduce diffuse DAB or staining in unexpected cells?
First compare a no-primary section with the test section, and check whether the DAB appears over structures that lack interpretable cell morphology (standard IHC practice). The pictured paraffin-section procedure used 10% goat-serum block, 2 μg/ml primary antibody overnight at 4°C, and DAB detection; its caption identifies antibody A16132-1 (caption A16132-1). Treat those settings as details of that pictured procedure when adjusting block or primary concentration (caption A16132-1; standard IHC practice). Include a peroxidase block and optimise development time to assess endogenous enzyme signal and diffuse precipitate (standard chromogenic IHC practice).
How should I quantify MGAM staining across sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the compartment before scoring: measure apical staining in evaluable enterocytes separately from any leukocyte cytoplasmic signal (UniProt O43451: brush border; HPA: cytoplasmic staining in leukocyte subsets). For epithelial cells, report the percentage at each intensity grade 0–3 and calculate an H-score on a 0–300 scale (standard IHC scoring practice). Normalise positive counts to evaluable enterocytes, or apical signal to measured brush-border length, and report the chosen denominator (standard image-analysis practice). Exclude folds, detached epithelium and damaged edges using the same rules across slides; keep retrieval and DAB development consistent for comparisons (standard IHC practice).
How do I distinguish true MGAM staining from artefact?
A convincing small-intestinal result follows enterocyte microvilli at the apical border, consistent with the reported localisation (HPA: high in enterocyte microvilli; UniProt O43451: brush border). Kidney proximal-tubule microvilli and leukocyte subsets have different reported patterns, so interpret each cell population in its own compartment (HPA tissue IHC). Be cautious with nuclear or diffuse staining, isolated section edges and necrotic areas, particularly when the no-primary section also develops colour (UniProt O43451 topology; standard IHC practice). Check peroxidase blocking and DAB development when signal appears in unexpected sites; the HPA reliability note also reports disregarded presumed off-target binding (standard IHC practice; HPA: Enhanced reliability description).
Boster reagents
Best MGAM / Maltase-glucoamylase IHC Antibodies
A07347 lists IHC and human, mouse and rat reactivity (catalog applications/reactivity). Its IHC images show mouse and rat colon paraffin sections (catalog image captions); no IF image is supplied (catalog IF images).
Real IHC data
Anti-MGAM Antibody ®
Cat # A07347
Only A07347 will render; it lists IHC and human, mouse and rat reactivity (catalog applications/reactivity). Its IHC images show mouse and rat colon paraffin sections stained with 2 μg/ml primary antibody (catalog image captions).
Which to pick: For tissue IHC, A07347 is the listed option: its mouse and rat paraffin-section captions describe EDTA retrieval at pH 8.0 (catalog image captions), but the fixative is unreported and the captions name a different antibody identifier (catalog image captions; catalog SKU). For cross-species work, A07347 lists human, mouse and rat reactivity, while the shown IHC images cover mouse and rat only; clone type is unreported (catalog reactivity; catalog image captions; catalog clone field). No listed SKU has an IF/ICC application or IF image, so this payload supports no IF/ICC pick (catalog applications; catalog IF images).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry O43451 (MGA_HUMAN, Maltase-glucoamylase).
- Human Protein Atlas. MGAM tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. MGAM subcellular location (ICC-IF): Membrane.
- Human Protein Atlas. MGAM antibody validation summary (1 antibodies).
- An apparent homozygous deletion in maltase-glucoamylase, a lesson in the evolution of SNP arrays. Molecular genetics and metabolism 2012 — PMC3520432.
- Proteomic analysis-based discovery of a novel biomarker that differentiates intestinal Behçet's disease from Crohn's disease. Scientific reports 2021 — PMC8155054.
- PubMed PMID:9446624 — UniProt-cited evidence.
- PubMed PMID:12853948 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for MGAM (Maltase-glucoamylase). Expected localisation Apical microvilli; leukocyte cytoplasm (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A07347). Validated IHC antibody: A07347 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Duodenum (Enterocytes - Microvilli); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded rat colon tissue; fixative not specified (datasheet A07347); 2. Fixation: Image fixative and duration unreported (datasheet A07347); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat retrieval: EDTA pH 8.0 (datasheet A07347); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A07347); 8. Primary antibody: Rabbit anti-MGAM, 2-5 μg/ml (datasheet A07347); 9. Primary incubation: Overnight at 4 °C (datasheet A07347). Watch for: Fixation: Keep fixation consistent across paraffin sections. (standard IHC practice; not target-specific); Caveat: Presumed off-target staining was observed and disregarded (HPA tissue IHC); Isoform / epitope: 2 isoforms; check epitopes against cytoplasmic 1–13 and luminal 35–2753 regions (UniProt); Regulation: High expression in small intestine (UniProt). Evidence: UniProt O43451, HPA tissue IHC · Enhanced, HPA ICC-IF · Membrane, Datasheet A07347, PMC3520432, PMC8155054. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/MGAM/immunohistochemistry-ihc-guide.