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MLST8 / Target of rapamycin complex subunit LST8 · IHC design guide
Design Immunohistochemistry for MLST8
Plan MLST8 chromogenic IHC in paraffin sections using the catalog antibody’s human IHC examples (datasheet A05357-2). Assess cytoplasmic staining by cell type and intensity, allowing for low consistency between antibody staining and RNA expression (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
MLST8 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 | Cytoplasmic in tissue (HPA tissue IHC); lysosomal membrane location (UniProt) | |
| Staining pattern | Cytoplasmic staining in most tissues (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A05357-2) | |
| Positive control | Adrenal gland+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) | |
| Caveat | Low consistency between antibody staining and RNA expression (HPA tissue IHC) | |
| Regulation | No expression regulator specified (UniProt) | |
| Isoform / epitope | 4 isoforms; no transmembrane segment; epitope coverage unknown (UniProt) |
Section 1
Recommended MLST8 IHC & IF Protocols
The catalog antibody’s IHC-P protocol (datasheet A05357-2) is accompanied by one published MLST8 immunoperoxidase protocol (PMC4408021).
| Sample | Paraffin-embedded human esophageal squamous carcinoma tissue; fixative not specified (datasheet A05357-2) |
| Fixation | Image fixative and duration unreported (datasheet A05357-2); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A05357-2); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A05357-2) |
| Primary antibody | Rabbit anti-MLST8, 2-5 μg/ml (datasheet A05357-2) |
| Primary incubation | Overnight at 4 °C (datasheet A05357-2) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet A05357-2) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | MLST8-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic expression in most tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA retrieval at pH 8.0 (datasheet A05357-2); the published protocol specifies pressurized heat but no retrieval buffer (PMC4408021).
Section 2
What Is the Expected MLST8 Staining Pattern?
MLST8 should usually appear cytoplasmic in tissue IHC, including medium staining in glandular, respiratory epithelial, hematopoietic and selected glial cells (HPA tissue IHC). UniProt also places MLST8 in the cytoplasm and at lysosome membranes, with no transmembrane segment (UniProt Q9BVC4). Treat this as a working pattern: HPA rates its tissue IHC evidence Approved but reports low consistency between antibody staining and RNA expression (HPA tissue IHC).
| Cytoplasmic staining in appendix glandular cells or bone marrow hematopoietic cells. | This matches the reported medium signal in those cells (HPA tissue IHC). Judge the cell type and compartment together; intensity alone cannot establish specificity, particularly given the reported low agreement with RNA expression (HPA tissue IHC). |
| Strong, nucleus-only staining in tissue sections, with little cytoplasmic signal. | This departs from the predominant cytoplasmic tissue pattern and warrants an artefact check (HPA tissue IHC). Nuclear signal is not automatically false: HPA reports approved nucleoplasmic localization in ICC-IF, a different application (HPA subcellular ICC-IF). |
| Prominent signal in adipocytes while expected glandular or hematopoietic cells are weak. | HPA reports adipocytes as not detected, versus medium signal in several glandular populations and bone marrow hematopoietic cells (HPA tissue IHC). Consider cross-reactivity or endogenous detection activity; neither cause is established by the pattern alone (standard IHC practice). |
| Diffuse color across cells and surrounding tissue, without clear cytoplasmic boundaries. | This is hard to score as cellular MLST8 staining (standard IHC practice). Check background from the detection workflow before interpreting intensity; HPA describes cytoplasmic expression in most tissues, not a diffuse tissue-wide deposit (HPA tissue IHC). |
| No signal in appendix glandular cells despite interpretable tissue morphology. | HPA reports medium staining in these cells, so first check the IHC run and whether the intended cell population is present (HPA tissue IHC; standard IHC practice). A single blank section cannot establish MLST8 absence because HPA reports limited staining–RNA consistency (HPA tissue IHC). |
💡Expected MLST8 appearanceA credible positive is discernible cytoplasmic staining of the reported cells, often medium in listed examples; diffuse deposits or isolated adipocyte staining call for checks (HPA tissue IHC; standard IHC practice).
| Tissue and cell population | MLST8 is broadly expressed (UniProt Q9BVC4); HPA reports cytoplasmic staining in most tissues, medium signal in several named cell populations, low signal in hippocampal glia and ovarian stroma, and no detected signal in adipocytes (HPA tissue IHC). Score the relevant cell population rather than the section as a whole. |
| IF/ICC Q: Should its pattern match tissue IHC? | HPA's approved ICC-IF localization is mainly nucleoplasmic, with additional Golgi apparatus and cell junction signal (HPA subcellular ICC-IF). This differs from HPA's mainly cytoplasmic tissue IHC profile (HPA tissue IHC). Evaluate each application against its own evidence; the ICC-IF observation does not establish a nuclear tissue IHC expectation. |
| Nutrient-dependent location | UniProt describes recruitment of mTORC1 to lysosome membranes according to amino acid availability and lists MLST8 in the cytoplasm and at lysosome membranes (UniProt Q9BVC4). The supplied tissue IHC profile does not specify a punctate staining requirement (HPA tissue IHC); avoid scoring puncta alone as proof of MLST8. |
| Validation and isoforms | Three listed antibodies are Approved for IHC, while HPA reports low consistency between tissue staining and RNA expression (HPA antibodies; HPA tissue IHC). UniProt lists four MLST8 isoforms, but the supplied evidence gives no epitope coverage for an antibody (UniProt Q9BVC4); do not infer which isoforms a stain detects. |
| Situation | Likely cause | Next action |
|---|---|---|
| A reported medium-positive population is blank or unexpectedly faint. | The result conflicts with the reported tissue pattern, but could reflect an IHC workflow problem or sample variation (HPA tissue IHC; standard IHC practice). | Verify the named cells are present, review the catalog antibody's IHC-P procedure, and check retrieval, detection and counterstain against a working run (standard IHC practice). Do not assign an MLST8-specific fixation effect: none is supplied. |
| Adipocytes stain prominently. | HPA reports adipocytes as not detected, making this pattern discordant; nonspecific antibody binding or endogenous detection activity are possibilities (HPA tissue IHC; standard IHC practice). | Inspect a matched detection control and staining distribution, then compare with a reported positive cell population (standard IHC practice; HPA tissue IHC). Treat the adipocyte observation as a specificity question, not proof of a particular mechanism. |
| The tissue section shows predominantly nuclear staining. | This differs from HPA's cytoplasmic tissue IHC profile, although HPA separately reports approved nucleoplasmic ICC-IF localization (HPA tissue IHC; HPA subcellular ICC-IF). | Check cellular boundaries and background, then compare the tissue pattern with the catalog antibody's IHC evidence (standard IHC practice). Record the application difference before calling the nuclear signal an artefact. |
| Broad, hazy chromogen obscures cell boundaries. | Background from blocking, washing or detection may prevent compartment scoring (standard IHC practice); the HPA tissue description requires an interpretable cytoplasmic pattern (HPA tissue IHC). | Review blocking and washes, inspect a detection control, and reassess only cells with clear boundaries (standard IHC practice). Do not count uniform haze as medium cytoplasmic staining. |
| Only fine puncta are visible, with no convincing cellular pattern. | Lysosome membrane association is biologically plausible under amino acid-dependent conditions (UniProt Q9BVC4), but the supplied tissue IHC evidence does not validate puncta as a stand-alone readout (HPA tissue IHC). | Check whether puncta lie within the expected stained cells, assess background and compare the overall pattern with HPA tissue IHC (standard IHC practice; HPA tissue IHC). Report puncta descriptively without assigning them to lysosomes from chromogenic IHC alone. |
Experiment evidence
IHC & IF images showing MLST8 staining
A05357-2 · IHCIHC analysis of MLST8 using anti-MLST8 antibody (A05357-2). MLST8 was detected in a paraffin-embedded section of human esophageal squamous c
A05357-2 · IHCIHC analysis of MLST8 using anti-MLST8 antibody (A05357-2). MLST8 was detected in a paraffin-embedded section of human liver cancer tissue.
A05357-2 · IFIF analysis of MLST8 using anti-MLST8 antibody (A05357-2) and anti-Beta Tubulin antibody (M01857-3). MLST8 was detected in immunocytochemica
A05357-1 · IHCImmunohistochemistry of GbL in mouse brain tissue with GbL antibody at 10 μg/mL.
A05357-1 · IFImmunofluorescence of GBL in Mouse Brain cells with GBL antibody at 10 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000167965-MLST8/tissue/cerebral+cortex#imid_17257979
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000167965-MLST8/tissue/colon#imid_17257921
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000167965-MLST8/tissue/liver#imid_17257906
HPA · PancreasHuman Protein Atlas IHC, Pancreas. Source: https://www.proteinatlas.org/ENSG00000167965-MLST8/tissue/pancreas#imid_17257865
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA041841; green = MLST8, blue = nucleus, red = microtubules.
HPA · ICC-IF HEK293Human Protein Atlas immunofluorescence, HEK293, antibody HPA041841; green = MLST8, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for MLST8 IHC & IF
🧪Run breast first: glandular cells should show medium MLST8 staining (HPA: breast glandular cells, Medium). Use adipose tissue as the negative tissue; adipocytes within the breast slide should provide an internal background check, though their staining must be assessed directly (HPA: adipose tissue adipocytes, Not detected).
Positive control tissue: Adrenal gland (Glandular cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show MLST8 in HEK293, MCF-7, U2OS, NIH 3T3, with annotated localisation: Nucleoplasm (approved) (HPA subcellular).
Technical controls: Include a no-primary, secondary-only slide and a concentration-matched rabbit IgG isotype control (selected-SKU caption: rabbit primary antibody). Use MLST8 knockout material as a biological specificity control, and quench endogenous peroxidase before chromogenic detection (standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported in the supplied evidence, and the selected-SKU tissue-IHC caption does not state a fixative (selected-SKU caption: fixative unreported). The caption uses heat retrieval in EDTA at pH 8.0 for a paraffin section, so retrieval is a practical starting point to validate for breast tissue (selected-SKU caption: EDTA retrieval, pH 8.0). The supplied evidence does not establish that frozen sections or IF are easier, or identify a breast-specific artefact; check background in adipocytes and other structures when scoring (HPA: adipose tissue adipocytes, Not detected; standard IHC practice).
HPA tissue IHC evidence for MLST8
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Medium | Protein (IHC) | HPA → |
| Breast | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bronchus | Respiratory 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 → |
Section 3
Advanced MLST8 IHC Tips
Troubleshoot MLST8 staining in paraffin sections by checking retrieval, compartment, controls and scoring before interpreting changes in signal.
How should I retrieve MLST8 in paraffin sections when staining is weak?
Begin with heat-mediated retrieval in EDTA at pH 8.0 (datasheet A05357-2). The catalog antibody produced a chromogenic signal in a paraffin section using that retrieval condition, followed by 2 μg/ml primary antibody overnight at 4°C (datasheet A05357-2). If signal is weak, check that sections received comparable heating, cooling and washing before changing the buffer (standard IHC practice). Compare any fallback retrieval condition on adjacent sections while holding antibody concentration and detection constant (standard IHC practice). Judge improvement by cellular staining relative to a no-primary control, since stronger diffuse colour alone does not establish MLST8 specificity (standard IHC practice).
Could fixation explain uneven MLST8 staining across paraffin sections?
Target-specific sensitivity of MLST8 to fixation is unknown from the supplied evidence; the selected paraffin-section caption does not state a fixative (datasheet A05357-2). Record the fixative, duration and processing history for every specimen before comparing staining (standard IHC practice). Stain 2 adjacent sections from each block in the same run, using EDTA at pH 8.0 and identical detection conditions (datasheet A05357-2; standard IHC practice). Examine whether weak signal follows a specimen or an entire staining run, and review tissue preservation alongside the no-primary control (standard IHC practice). Do not assign a fixation effect to MLST8 without a controlled comparison (standard IHC practice).
Which compartments should count as plausible MLST8 staining in tissue?
Expect predominantly cytoplasmic staining in tissue sections, while allowing for context-dependent association with lysosome membranes (HPA tissue IHC; UniProt Q9BVC4 subcellular location). MLST8 has no transmembrane segment, so a continuous cell-surface rim would need independent validation before being scored as specific (UniProt Q9BVC4 topology; standard IHC practice). HPA also reports approved nucleoplasmic, Golgi and cell-junction locations from subcellular imaging, which differ from its mainly cytoplasmic tissue-IHC profile (HPA subcellular; HPA tissue IHC). Score cytoplasmic and nuclear signal separately rather than combining them into one intensity value (standard IHC practice). Review cell identity, morphology and no-primary staining before accepting an unusual compartment (standard IHC practice).
Can this antibody distinguish MLST8 isoforms or modification-dependent staining?
MLST8 has 4 annotated isoforms, but the supplied product evidence does not map this antibody’s epitope or establish isoform selectivity (UniProt Q9BVC4 isoforms; datasheet A05357-2). The reference chain spans residues 1–326, with annotated modifications including Ser-7 and Thr-51 phosphorylation (UniProt Q9BVC4 processing; modified residues). Neither those modifications nor the absence of a transmembrane segment identifies which residues this antibody recognizes (UniProt Q9BVC4 modified residues; topology; datasheet A05357-2). If sections differ after retrieval, compare them under identical EDTA pH 8.0 conditions before proposing epitope masking (datasheet A05357-2; standard IHC practice). An isoform-specific or modification-specific conclusion requires independently mapped antibody recognition (standard IHC practice).
How can IF help resolve an ambiguous MLST8 IHC pattern?
Use IF as a separate validation experiment and multiplex MLST8 with a marker identifying the cell population being scored in the paraffin-section IHC (standard IF practice). Choose a red or far-red MLST8 fluorophore after checking each tissue’s autofluorescence and spectral overlap with the cell marker (standard IF practice). MLST8 has no transmembrane segment, while its annotated locations include cytoplasm and lysosome membrane; use permeabilisation appropriate for access to intracellular epitopes, whose precise orientation is not supplied (UniProt Q9BVC4 topology; subcellular location; standard IF practice). HPA subcellular imaging reports nucleoplasm, Golgi apparatus and cell junctions, so compare compartments explicitly across methods (HPA subcellular). Include single-colour and no-primary controls before interpreting overlap (standard IF practice).
What should I check when DAB obscures MLST8-positive cells?
The selected paraffin-section demonstration used 10% goat serum blocking, 2 μg/ml primary antibody overnight at 4°C, and peroxidase-based DAB detection (datasheet A05357-2). Start by comparing a no-primary section to the test section to identify colour unrelated to primary-antibody binding (standard IHC practice). Apply an endogenous-peroxidase block and check wash consistency before increasing retrieval or primary exposure (standard chromogenic IHC practice). Examine pigment, tissue edges and damaged areas separately from intact cellular staining, because each can complicate DAB interpretation (standard IHC practice). If background persists, titrate primary antibody around the documented condition while retaining EDTA at pH 8.0 and the same detection system (datasheet A05357-2; standard IHC practice).
How should I quantify MLST8 staining across different tissue regions? ⚠ ANSWER MARKED FOR VERIFICATION
Define the scored cell population and compartment before measuring MLST8, because HPA describes mainly cytoplasmic tissue staining while reporting other locations in subcellular imaging (HPA tissue IHC; HPA subcellular). For a cellular readout, record the percentage of positive cells and an H-score from 0–300, keeping nuclear and cytoplasmic scores separate (standard IHC practice). For spatial comparisons, report positive-cell density per mm² of viable tissue and the sampled area (standard IHC practice). Normalise comparisons to the same cell type, section area, staining run and exposure to detection reagents (standard IHC practice). Exclude necrotic or poorly preserved regions using a rule set before scoring (standard IHC practice).
How do I distinguish convincing MLST8 staining from artefact?
Look for reproducible cellular signal compatible with the mainly cytoplasmic tissue-IHC profile, while assessing any other compartment separately (HPA tissue IHC; HPA subcellular; standard IHC practice). A continuous membrane rim alone is difficult to reconcile with MLST8’s lack of a transmembrane segment and calls for independent validation (UniProt Q9BVC4 topology; standard IHC practice). Discount staining confined to tissue edges, necrosis or the no-primary control, including signal from endogenous enzyme activity (standard chromogenic IHC practice). Use a clearly identified cell population and matched processing when comparing sections, since HPA rates its tissue staining as Approved but reports low consistency with RNA expression (HPA tissue IHC; standard IHC practice). MLST8 staining alone cannot assign signal specifically to mTORC1 or mTORC2, because MLST8 belongs to both complexes (UniProt Q9BVC4 subunit).
Boster reagents
Best MLST8 / Target of rapamycin complex subunit LST8 IHC Antibodies
Two anti-MLST8 antibodies have IHC images from human paraffin carcinoma sections and mouse brain tissue, plus IF images from human cells and sections and mouse brain cells (catalog: image captions).
Real IHC data
Anti-MLST8 Antibody ®
Cat # A05357-2
Real IHC data
Anti-GBL MLST8 Antibody
Cat # A05357-1
A05357-2 shows IHC in paraffin sections of human esophageal, liver, lung, and rectal cancers, and IF in U2OS cells and human cancer sections (catalog: A05357-2 image captions). A05357-1 shows IHC in mouse brain tissue and IF in mouse brain cells (catalog: A05357-1 image captions).
Which to pick: Choose A05357-2 for human paraffin-section IHC and A05357-1 for mouse brain IHC, matching each antibody’s own image (catalog: IHC captions). For IF/ICC, A05357-2 lists both applications and has human cell and section images; A05357-1 lists IF and has a mouse brain cell image (catalog: applications and IF captions). Both list Human, Mouse, and Rat reactivity, while clonality and the fixative used for the paraffin-section IHC images are unreported (catalog: reactivity, clone fields, IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q9BVC4 (LST8_HUMAN, Target of rapamycin complex subunit LST8).
- Human Protein Atlas. MLST8 tissue IHC expression (reliability: Approved).
- Human Protein Atlas. MLST8 subcellular location (ICC-IF): Mainly localized to the nucleoplasm. In addition localized to the cell junctions and the Golgi apparatus..
- Human Protein Atlas. MLST8 antibody validation summary (3 antibodies).
- Activated mTOR Signaling in the RPE Drives EMT, Autophagy, and Metabolic Disruption, Resulting in AMD-Like Pathology in Mice. Aging cell 2025 — PMC12151893.
- CDK1/FBXW7 facilitates degradation and ubiquitination of MLST8 to inhibit progression of renal cell carcinoma. Cancer science 2022 — PMC8748215.
- mLST8 Promotes mTOR-Mediated Tumor Progression. PloS one 2015 — PMC4408021.
- Transcranial direct current stimulation exerts neuroprotective effects in Parkinson's disease by restoring Mlst8-mediated autophagic homeostasis. Journal of translational medicine 2026 — PMC12866061.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:15616553 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for MLST8 (Target of rapamycin complex subunit LST8). Expected localisation Cytoplasmic in tissue (HPA tissue IHC); lysosomal membrane location (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A05357-2). Validated IHC antibody: A05357-2 at 2-5 μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human esophageal squamous carcinoma tissue; fixative not specified (datasheet A05357-2); 2. Fixation: Image fixative and duration unreported (datasheet A05357-2); 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 A05357-2); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A05357-2); 8. Primary antibody: Rabbit anti-MLST8, 2-5 μg/ml (datasheet A05357-2); 9. Primary incubation: Overnight at 4 °C (datasheet A05357-2). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Low consistency between antibody staining and RNA expression (HPA tissue IHC); Isoform / epitope: 4 isoforms; no transmembrane segment; epitope coverage unknown (UniProt); Regulation: No expression regulator specified (UniProt). Evidence: UniProt Q9BVC4, HPA tissue IHC · Approved, HPA ICC-IF · Mainly localized to the nucleoplasm. In addition localized to the…, Datasheet A05357-2, PMC4408021. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/MLST8/immunohistochemistry-ihc-guide.