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FTL / Ferritin light chain · IHC design guide
Design Immunohistochemistry for FTL
Plan FTL staining in paraffin sections using its observed cytoplasmic tissue pattern and cell-specific controls (HPA tissue IHC). This guide covers fixation consistency, antibody incubation, chromogenic detection and interpretation of staining in renal tubules and hepatocytes (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
FTL 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 | Predominantly cytoplasmic in tissue sections (HPA tissue IHC) | |
| Staining pattern | Cytoplasmic staining; strong in renal tubules and hepatocytes (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet M01956-1) | |
| Positive control | Caudate+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 conditions consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Colon staining need not include endocrine cells (HPA tissue IHC; datasheet M01956-1) | |
| Regulation | Abundance varies by tissue (HPA tissue IHC) | |
| Isoform / epitope | No annotated isoforms; chain 2–175; no TM segment (UniProt) |
Section 1
Recommended FTL IHC & IF Protocols
The catalog antibody has an IHC-P protocol (datasheet M01956-1). These four published FTL IHC protocols provide tissue-specific examples (PMC10333082; PMC6755262; PMC5570299; PMC11367121).
| Sample | Paraffin-embedded human colon tissue; fixative not specified (datasheet M01956-1) |
| Fixation | Image fixative and duration unreported (datasheet M01956-1); 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 M01956-1); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet M01956-1) |
| Primary antibody | Rabbit monoclonal (clone ACBG-6) anti-FTL, 1:50 (datasheet M01956-1) |
| Primary incubation | Overnight at 4 °C (datasheet M01956-1) |
| Detection | HRP-conjugated secondary, DAB chromogen (datasheet M01956-1) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | FTL-positive staining in glial cells of caudate (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in most tissues, highly abundant renal tubules, liver, adrenal gland and red pulp of spleen. No signal in the no-primary control. |
💡Decision noteStart with EDTA pH 8.0 heat retrieval for the catalog antibody (datasheet M01956-1). Follow the cited retrieval method when reproducing a published assay.
Section 2
What Is the Expected FTL Staining Pattern?
FTL staining should be predominantly cytoplasmic in paraffin-section IHC, with strong signal expected in kidney proximal tubules, liver hepatocytes and lung macrophages (HPA tissue IHC: Enhanced reliability; High in each listed cell type). Cytosolic staining is consistent with the approved ICC-IF location, while vesicular or autolysosomal signal can fit the UniProt annotation (HPA subcellular: Cytosol; UniProt P02792 subcellular location). FTL has no transmembrane segment (UniProt P02792 topology).
| Strong cytoplasmic staining in kidney proximal tubules or liver hepatocytes, with recognizable tissue architecture. | This matches HPA's High cell-specific IHC observations and its cytoplasmic profile across most tissues (HPA tissue IHC: proximal tubules, High; hepatocytes, High). Compare the stained cells and compartment with the corresponding counterstained section; intensity alone cannot establish specificity (standard IHC practice). |
| Prominent nuclear-only staining, or a crisp continuous plasma-membrane outline without cytoplasmic signal. | That distribution does not match the approved cytosolic location or the reported cytoplasmic tissue pattern (HPA subcellular: Cytosol approved; HPA tissue IHC: cytoplasmic expression). Review antibody specificity and detection controls before interpreting it as FTL; UniProt also reports no transmembrane segment (UniProt P02792 topology). |
| Signal appears mainly in a cell population reported as undetected, while the expected positive cells are unstained. | Treat this as a discordant pattern that may reflect cross-reactivity or detection activity rather than confirmed FTL (HPA tissue IHC: adipocytes, myocytes and ovarian stroma cells, Not detected; standard IHC practice). HPA levels refer to the specified cell types, not every cell within those tissues (HPA tissue IHC). |
| Broad, fairly even chromogen covers cells and extracellular areas, obscuring cytoplasmic boundaries. | This is consistent with nonspecific background rather than a readable cellular pattern (standard IHC practice). Evaluate a no-primary control and compare background with the expected cell-restricted signal in proximal tubules or hepatocytes (standard IHC practice; HPA tissue IHC: both High). |
| Little or no signal in kidney proximal tubules or liver hepatocytes. | A negative result in these HPA High populations makes the run difficult to interpret (HPA tissue IHC: proximal tubules and hepatocytes, High). Check a suitable positive-control section and the staining workflow before concluding that the study sample lacks FTL (standard IHC practice). |
💡Expected FTL appearanceCall the stain positive when cytoplasmic chromogen is clear in kidney proximal tubules or liver hepatocytes at the expected High level (HPA tissue IHC: both High); isolated strong nuclear signal or uniform extracellular color is discordant (HPA subcellular: Cytosol approved; standard IHC practice).
| Cell-specific reference pattern | Use HPA's named cells when choosing controls: kidney proximal tubules, liver hepatocytes and lung macrophages are High, whereas adipocytes and skeletal-muscle myocytes are Not detected (HPA tissue IHC). A negative cell population does not make its entire tissue a negative control (HPA tissue IHC). |
| Adrenal-gland discrepancy | The HPA summary calls adrenal gland highly abundant, but its cell-level entry lists adrenal glandular cells as Not detected (HPA tissue IHC: profile; glandular cells, Not detected). Avoid using those glandular cells as an unqualified positive control; document the exact compartment and cell population assessed (HPA tissue IHC). |
| Subcellular interpretation | Cytosol is the approved ICC-IF location; UniProt also lists cytoplasmic vesicles, autophagosomes and autolysosomes (HPA subcellular: Cytosol approved; UniProt P02792 subcellular location). Chromogenic IHC can support a cytoplasmic pattern, but organelle assignment requires additional evidence (standard IHC practice). |
| Antibody evidence | Two catalog antibody records have Enhanced IHC status, HPA041602 and CAB020769 (HPA antibodies: IHC Enhanced). HPA describes Enhanced tissue reliability as high consistency between antibody staining and RNA expression data; that supports the reference pattern but does not validate every staining run (HPA tissue IHC: Enhanced reliability; standard IHC practice). |
| IF/ICC Q: What localisation should a separate IF/ICC guide expect? | A: Predominantly cytosolic signal (HPA subcellular: Cytosol approved); HPA lists ICC-IF images for A-549 and U2OS and marks HPA041602 ICC Approved (HPA subcellular; HPA antibodies). Those observations do not specify an IF/ICC protocol (HPA subcellular; HPA antibodies). |
| Situation | Likely cause | Next action |
|---|---|---|
| No stain in a kidney section selected as the positive control. | The control is informative only if proximal tubules are present and evaluable; those cells are High in the HPA record (HPA tissue IHC: proximal tubules, High). | Verify proximal tubules on the counterstain, then check that primary antibody, detection reagents and the run control were applied as intended (standard IHC practice). |
| Weak or patchy signal in expected positive cells. | The observed pattern falls below the HPA High reference in proximal tubules or hepatocytes; the record does not identify an FTL-specific fixation cause (HPA tissue IHC: both High). | Compare sections processed in the same run; review the catalog antibody's IHC-P instructions for retrieval and dilution, without assuming an unreported FTL-specific fixation effect (standard IHC practice). |
| Diffuse brown staining obscures cell boundaries. | Background may arise from insufficient blocking, residual detection activity or excess staining reagent (standard IHC practice). | Inspect a no-primary control, review blocking and washes, and adjust detection conditions according to the assay controls (standard IHC practice). |
| Staining is concentrated in nuclei or appears solely as a sharp membrane rim. | The distribution conflicts with HPA's approved cytosolic localisation and UniProt's lack of a transmembrane segment (HPA subcellular: Cytosol approved; UniProt P02792 topology). | Recheck compartment assignment against the counterstain and compare an independently validated IHC antibody or suitable specificity control (standard IHC practice; HPA antibodies: two Enhanced IHC records). |
| Unexpected signal is seen in adipocytes or skeletal-muscle myocytes. | Both named cell populations are Not detected in HPA IHC; nonspecific antibody binding or detection background is possible (HPA tissue IHC: adipocytes and myocytes, Not detected; standard IHC practice). | Confirm cell identity, inspect a no-primary control and compare a known-positive cell population in the same run (standard IHC practice; HPA tissue IHC: proximal tubules, High). |
| Adrenal glandular cells are negative despite the adrenal-gland summary. | The summary describes adrenal gland as highly abundant, while the cell-level adrenal glandular entry says Not detected (HPA tissue IHC: profile; glandular cells, Not detected). | Record which adrenal cells were scored and choose kidney proximal tubules or liver hepatocytes for a clearer positive reference (HPA tissue IHC: both High). |
Experiment evidence
IHC & IF images showing FTL staining
M01956-1 · IHCIHC analysis of Ferritin Light Chain using anti-Ferritin Light Chain antibody (M01956-1). Ferritin Light Chain was detected in a paraffin-em
M01956-1 · IHCIHC analysis of Ferritin Light Chain using anti-Ferritin Light Chain antibody (M01956-1). Ferritin Light Chain was detected in a paraffin-em
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000087086-FTL/tissue/cerebral+cortex#imid_12925359
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000087086-FTL/tissue/colon#imid_12925285
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000087086-FTL/tissue/liver#imid_12925278
HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000087086-FTL/tissue/kidney#imid_12925279
HPA · ICC-IF A-549Human Protein Atlas immunofluorescence, A-549, antibody HPA041602; green = FTL, blue = nucleus, red = microtubules.
HPA · ICC-IF A-549Human Protein Atlas immunofluorescence, A-549, antibody HPA041602; green = FTL, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for FTL IHC & IF
🧪Run kidney first: proximal tubule cell bodies should stain strongly (HPA: High in kidney proximal tubules); use adipose tissue adipocytes as the negative comparison (HPA: Not detected in adipocytes). On the kidney slide, cells outside proximal tubules should show only background staining if used as internal negative comparators, but HPA does not identify a confirmed negative kidney cell type.
Positive control tissue: Caudate (Glial cells, HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show FTL in A-549, U2OS, with annotated localisation: Cytosol (approved) (HPA subcellular).
Technical controls: Include a no-primary (secondary-only) control, a host- and class-matched rabbit IgG isotype control (caption: rabbit primary antibody), and FTL-knockout material or immunizing-peptide competition if available. For HRP/DAB detection, quench endogenous peroxidase; assess endogenous biotin if using biotin-based detection, and check kidney autofluorescence if using IF (standard IHC/IF practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the exact M01956-1 paraffin-section caption does not state the fixative (caption: fixative not stated). That caption uses heat-mediated EDTA retrieval at pH 8.0, but retrieval dependence is untested in the supplied evidence (caption: EDTA retrieval). Frozen sections are not established as easier; ICC-IF provides a cytosolic readout in A-549 and U2OS cells (HPA: Cytosol, approved), while kidney autofluorescence needs a background check for IF (standard IF practice).
HPA tissue IHC evidence for FTL
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High 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 |
|---|---|---|---|---|
| Caudate | Glial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Granular cells - cytoplasm/membrane | High | Protein (IHC) | HPA → |
| Cerebral cortex | Glial cells | High | Protein (IHC) | HPA → |
| Kidney | Proximal tubules (cell body) | High | Protein (IHC) | HPA → |
| Liver | Hepatocytes | High | 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 → |
| Colon | Endocrine cells | Not detected | Protein (IHC) | HPA → |
| Fallopian tube | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Ovary | Ovarian stroma cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced FTL IHC Tips
Use the catalog antibody’s paraffin-section IHC conditions as the starting point, then assess staining by cell type, compartment and appropriate controls.
Which antigen retrieval conditions should I use for FTL in paraffin sections?
Start with heat-mediated retrieval in EDTA at pH 8.0 (datasheet M01956-1). The selected paraffin-section image used this retrieval before incubation with the catalog antibody at 1:50 overnight at 4°C; its caption does not state the fixative (caption M01956-1). If staining is weak, vary heating time on matched sections while keeping section thickness, antibody incubation and DAB development constant (standard IHC practice). Compare signal in hepatocytes or kidney proximal tubules with a no-primary control, and check whether stronger retrieval also raises background (HPA: high staining in those cell types; standard IHC practice).
How should I assess whether fixation is masking FTL staining?
The selected paraffin-section caption does not identify a fixative, so target-specific FTL sensitivity to fixation is unknown (caption M01956-1). Record the actual fixative and fixation duration for each specimen, then compare matched sections using the same EDTA pH 8.0 retrieval and 1:50 primary dilution (datasheet M01956-1; standard IHC practice). Assess preserved morphology alongside cytoplasmic signal, because poor morphology makes cell-level interpretation unreliable (HPA: predominantly cytoplasmic tissue staining; standard IHC practice). Include a consistently processed positive tissue section and a no-primary control in each comparison; neither HPA tissue patterns nor FTL topology establishes a fixation-specific effect (HPA tissue IHC; UniProt P02792 topology; standard IHC practice).
Where should convincing FTL staining appear in tissue sections?
Look first for cytoplasmic staining: HPA reports cytoplasmic expression across most tissues and an approved cytosolic location (HPA tissue IHC; HPA subcellular). Vesicular or lysosome-associated puncta can also be biologically plausible because FTL is annotated in cytoplasmic vesicles, autophagosomes and autolysosomes (UniProt P02792 subcellular). Use cell identity as a second check: hepatocytes, kidney proximal tubules and lung macrophages have high reported staining (HPA tissue IHC). FTL has no transmembrane segment, so an isolated sharp membrane rim requires independent validation before being scored as FTL (UniProt P02792 topology; standard IHC practice). Compare that pattern with the no-primary section and surrounding cytoplasm (standard IHC practice).
How can I judge epitope accessibility and FTL specificity?
The record lists 0 isoforms, a mature chain spanning residues 2–175, and a ferritin-like diiron domain at residues 7–156 (UniProt P02792 processing, isoforms and domains). It also records N-acetylserine at residue 2 and 0 glycosylation sites, but the supplied antibody caption does not define its epitope (UniProt P02792 modified residues and glycosylation; caption M01956-1). Do not assign weak staining to an isoform or modification without epitope evidence (standard IHC practice). FTL assembles with ferritin heavy-chain subunits in a 24-subunit shell; establish antibody specificity with appropriate orthogonal evidence before interpreting unusual staining (UniProt P02792 subunit; standard IHC practice).
How should I investigate FTL localisation by multiplex IF?
Treat IF/ICC as a separate validation experiment: the selected antibody evidence describes chromogenic staining of a paraffin section, while HPA lists ICC/IF images for A-549 and U2OS (caption M01956-1; HPA subcellular). Multiplex FTL with a marker identifying the cell population under study, then evaluate whether FTL signal falls in its expected cytosolic compartment (HPA: approved cytosolic location; standard IF practice). Choose a fluorophore channel after checking the specimen’s autofluorescence and include single-label controls for channel bleed-through (standard IF practice). Because FTL lacks a transmembrane segment, use permeabilisation appropriate for intracellular antigen access and verify that it preserves cell morphology (UniProt P02792 topology; standard IF practice).
What should I check when DAB staining looks diffuse or nonspecific?
Compare the stained section with no-primary and secondary-only controls to identify reagent-associated background (standard IHC practice). The selected image used 10% goat serum blocking, a 1:50 primary incubation overnight at 4°C, and peroxidase-linked detection with DAB (caption M01956-1). If background rises across many cell types, check endogenous peroxidase blocking, washing and DAB development time before changing the primary concentration (standard chromogenic IHC practice). Preserve enough signal to evaluate hepatocytes or kidney proximal tubules, which show high reported staining (HPA tissue IHC). Record background in the same compartments used for scoring so threshold changes remain comparable across sections (standard IHC practice).
How should I quantify FTL staining across specimens? ⚠ ANSWER MARKED FOR VERIFICATION
Define the tissue compartment and cell population before scoring, because reported FTL abundance differs by cell type (HPA tissue IHC; standard IHC practice). For a defined population, report the percentage of positive cells and an intensity-weighted H-score; for sparse positive cells, report positive-cell density per mm² of viable tissue (standard IHC practice). Normalise counts to the assessed viable area or eligible cell count, and use the same staining threshold and DAB development conditions throughout the comparison (standard IHC practice). Score hepatocytes separately from other liver cells, or proximal tubules separately from other kidney structures, when those are the populations of interest (HPA: high staining in hepatocytes and proximal tubules; standard IHC practice).
How can I distinguish genuine FTL signal from staining artefacts?
A credible result aligns cell identity with predominantly cytoplasmic staining: HPA reports high signal in hepatocytes, kidney proximal tubules and lung macrophages, and an approved cytosolic location (HPA tissue IHC; HPA subcellular). Assess unexpected nuclear-only or membrane-rim staining against morphology and controls before calling it FTL (UniProt P02792 topology; standard IHC practice). Exclude tissue edges, necrotic areas and deposits that stain similarly in no-primary controls, and investigate residual endogenous peroxidase if DAB appears without primary antibody (standard chromogenic IHC practice). FTL stores iron, but staining alone does not measure iron content or prove altered iron handling (UniProt P02792 function; standard IHC interpretation).
Boster reagents
Best FTL / Ferritin light chain IHC Antibodies
The catalog lists two anti-FTL antibodies for IHC, but only M01956-1 has a tissue image: a paraffin section of human colon (catalog applications; M01956-1 image caption). Neither lists IF/ICC (catalog applications).
Real IHC data
Anti-Ferritin Light Chain FTL Monoclonal Antibody
Cat # M01956-1
M01956-1 lists IHC and human, mouse and rat reactivity; its image shows staining in a paraffin section of human colon (catalog applications/reactivity; M01956-1 image caption). A01956-1 lists IHC and human and rat reactivity, with no IHC image supplied (catalog applications/reactivity; catalog image fields).
Which to pick: Choose M01956-1 for paraffin-section tissue IHC: it is monoclonal, and its human colon caption documents EDTA retrieval at pH 8.0 and a 1:50 primary dilution; the fixative is unreported (catalog clone field; M01956-1 image caption). For work across the listed species, M01956-1 covers human, mouse and rat, while A01956-1 is polyclonal and lists human and rat; the tissue image documents human colon only (catalog reactivity/clonality; M01956-1 image caption). Neither SKU lists IF/ICC validation or an IF image, so there is no supported IF/ICC pick here (catalog applications; catalog image fields).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P02792 (FRIL_HUMAN, Ferritin light chain).
- Human Protein Atlas. FTL tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. FTL subcellular location (ICC-IF): Localized to the cytosol..
- Human Protein Atlas. FTL antibody validation summary (2 antibodies).
- Construction of a T-cell exhaustion-related gene signature for predicting prognosis and immune response in hepatocellular carcinoma. Aging 2023 — PMC10333082.
- Ferritin expression in the periodontal tissues of primates. European journal of histochemistry : EJH 2019 — PMC6755262.
- Transferrin receptor-1 and ferritin heavy and light chains in astrocytic brain tumors: Expression and prognostic value. PloS one 2017 — PMC5570299.
- Ferritin light chain as a potential biomarker for the prognosis of liver hepatocellular carcinoma. Heliyon 2024 — PMC11367121.
- PubMed PMID:3840162 — UniProt-cited evidence.
- PubMed PMID:3858810 — UniProt-cited evidence.
- PubMed PMID:3754330 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for FTL (Ferritin light chain). Expected localisation Predominantly cytoplasmic in tissue sections (HPA tissue IHC). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet M01956-1). Validated IHC antibody: M01956-1 at 1:50 (the product's own IHC validation image is shown). Controls (HPA): positive Caudate (Glial cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human colon tissue; fixative not specified (datasheet M01956-1); 2. Fixation: Image fixative and duration unreported (datasheet M01956-1); 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 M01956-1); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet M01956-1); 8. Primary antibody: Rabbit monoclonal (clone ACBG-6) anti-FTL, 1:50 (datasheet M01956-1); 9. Primary incubation: Overnight at 4 °C (datasheet M01956-1). Watch for: Fixation: Keep fixation conditions consistent across sections. (standard IHC practice; not target-specific); Caveat: Colon staining need not include endocrine cells (HPA tissue IHC; datasheet M01956-1); Isoform / epitope: No annotated isoforms; chain 2–175 ; no TM segment (UniProt); Regulation: Abundance varies by tissue (HPA tissue IHC). Evidence: UniProt P02792, HPA tissue IHC · Enhanced, HPA ICC-IF · cytosol., Datasheet M01956-1, PMC10333082, PMC6755262. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/FTL/immunohistochemistry-ihc-guide.