DAZL / Deleted in azoospermia-like · IHC design guide

Design Immunohistochemistry for DAZL

Plan chromogenic DAZL IHC-P using testis pachytene spermatocytes as a positive control (HPA tissue IHC). This guide covers expected localisation (UniProt) and the IHC-validated antibody’s 0.5–1 μg/ml working range (datasheet A02069-2).

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

Immunohistochemistry protocol sheet for DAZL (IHC for DAZL): expected localisation Expected predominantly cytoplasmic; can be nuclear in spermatogonia (UniProt), antibody A02069-2, validated IHC image, and IHC protocol steps — Printable **DAZL** IHC protocol sheet — expected localisation Expected predominantly cytoplasmic; can be nuclear in spermatogonia (UniProt), antibody A02069-2, controls and protocol steps. Open the full DAZL IHC guide →

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DAZL 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	Expected predominantly cytoplasmic; can be nuclear in spermatogonia (UniProt)
	Staining pattern	High in pachytene spermatocytes; compartment unreported (HPA tissue IHC)
	Antigen retrieval	EDTA pH 8.0 HIER, heat-mediated (datasheet A02069-2)
	Positive control ⓘ	Testis
	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	Localisation changes with meiotic stage (UniProt)
	Regulation	Testis specific expression (UniProt)
	Isoform / epitope	2 isoforms; epitope differences unreported (UniProt)

Section 1

Recommended DAZL IHC & IF Protocols

The catalog antibody protocol uses EDTA retrieval (datasheet: A02069-2). The published chromogenic IHC option stains human glioblastoma tissue arrays (PMC7368788).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human testies cancer tissue; fixative not specified (datasheet A02069-2)
Fixation	Image fixative and duration unreported (datasheet A02069-2); 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 A02069-2); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% goat serum (datasheet A02069-2)
Primary antibody	Rabbit anti-DAZL, 0.5-1μg/ml (datasheet A02069-2)
Primary incubation	Overnight at 4 °C (datasheet A02069-2)
Detection	Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A02069-2)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	DAZL-positive staining in pachytene spermatocytes of testis (HPA tissue IHC: High). HPA tissue profile: High expression in testis. No signal in the no-primary control.

💡Decision noteStart with heat-mediated EDTA at pH 8.0 for the catalog antibody (datasheet: A02069-2); the published protocol uses citrate at pH 6.0 (PMC7368788).

Section 2

What Is the Expected DAZL Staining Pattern?

DAZL staining is expected in testicular germ cells, with high IHC signal reported in pachytene spermatocytes (HPA: testis IHC, Enhanced reliability). DAZL is predominantly cytoplasmic, while nuclear localisation can occur earlier in germ cell development (UniProt Q92904: subcellular location). It has no transmembrane segment, so a membrane outline is not the expected pattern (UniProt Q92904: topology).

What am I looking at on my slide?
Strong cytoplasmic staining in pachytene spermatocytes, with little staining elsewhere in the section.	This matches the reported high testis signal (HPA: pachytene spermatocytes). Predominantly cytoplasmic localisation is consistent with UniProt Q92904. Assess the labelled cells within the seminiferous tubules; a dark field alone does not establish cell specific staining (general IHC practice).
Nuclear staining, or a sharp outline around cells, dominates the positive region.	Nuclear DAZL can occur in earlier germ cells, so interpret it in relation to cell stage (UniProt Q92904: subcellular location). A dominant membrane outline has no support from DAZL topology (UniProt Q92904: no transmembrane segment). Review morphology and detection controls before calling either pattern specific (general IHC practice).
Strong staining appears in adipocytes or other cells listed as negative.	HPA reports DAZL as not detected in adipocytes from adipose tissue and breast, and in several other sampled cell types (HPA: tissue IHC). Check for cross reactivity or endogenous detection activity; the HPA result applies to the listed cells and samples, not every cell in those organs (general IHC interpretation).
Diffuse colour covers tissue, stroma or blank regions without a clear germ cell pattern.	This does not reproduce the cell restricted testis pattern (HPA: testis IHC). Possible general IHC causes include nonspecific binding, incomplete blocking, residual endogenous enzyme activity or excessive development. Compare a no primary control and review wash and detection steps before assigning the colour to DAZL (general IHC practice).
Pachytene spermatocytes lack visible signal in a known positive testis section.	A negative result conflicts with the high signal reported for these cells (HPA: testis IHC). First confirm that the expected cells are present and that the control run worked. Then review antibody performance, retrieval and detection conditions as general IHC variables; no DAZL specific fixation sensitivity is established here.

💡Expected DAZL appearanceCall the result positive when pachytene spermatocytes show high, chiefly cytoplasmic signal (HPA: testis IHC; UniProt Q92904: localisation); broad staining of HPA negative cells or a dominant membrane outline warrants investigation (HPA: tissue IHC; UniProt Q92904: topology).

How each factor affects the staining
Germ cell stage and compartment	DAZL is predominantly cytoplasmic; UniProt also describes nuclear localisation in spermatogonia until near the end of meiotic prophase, followed by cytoplasmic localisation (UniProt Q92904). Interpret nuclei alongside cell stage.
Choice of tissue control	Testis contains high staining pachytene spermatocytes and is the strongest supplied positive reference (HPA: testis IHC). HPA lists selected cells in other tissues as not detected; use their stated cell types when assessing negative staining.
Antibody validation	The tissue profile has Enhanced reliability, reflecting consistency between staining and RNA data (HPA: tissue IHC). HPA019777 has Enhanced IHC validation and HPA047113 has Supported IHC validation (HPA: antibodies); these labels do not validate every staining pattern.
Topology and interpretation	DAZL has no transmembrane segment and no signal peptide (UniProt Q92904: topology and processing). A membrane rim should prompt review of staining specificity; these annotations alone do not predict retrieval needs or fixation sensitivity.
IF/ICC: is a cellular pattern established?	HPA gives no main subcellular location or ICC-IF image set for DAZL (HPA: subcellular). UniProt describes stage dependent nuclear and cytoplasmic localisation, but this is not an HPA ICC-IF validation or an IF protocol (UniProt Q92904).

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
No staining in pachytene spermatocytes of a testis section.	The expected cell population may be absent from the examined area, or the IHC run may have failed (HPA: high in pachytene spermatocytes; general IHC practice).	Verify morphology and the positive control, then review the antibody, retrieval and detection workflow (general IHC practice). Do not infer a DAZL specific fixation effect from this result.
Signal appears mainly as a membrane outline.	A membrane dominant pattern conflicts with the absence of a DAZL transmembrane segment (UniProt Q92904: topology); nonspecific staining is possible (general IHC practice).	Compare the no primary control, inspect whether the outline tracks tissue edges, and reassess antibody specificity (general IHC practice).
Nuclear signal is treated as an automatic failure.	UniProt describes nuclear DAZL in spermatogonia and a later shift toward cytoplasmic localisation (UniProt Q92904: subcellular location).	Identify the labelled germ cell stage and compare the surrounding cytoplasmic pattern before rejecting the section (UniProt Q92904; general IHC interpretation).
Adipocytes or another HPA negative cell type stain strongly.	The signal conflicts with a cell specific HPA not detected observation; cross reactivity or endogenous detection activity is possible (HPA: tissue IHC; general IHC practice).	Confirm cell identity, compare a no primary control, and review blocking and detection chemistry (general IHC practice).
Diffuse chromogen obscures germ cell boundaries.	Background may reflect nonspecific antibody binding, residual endogenous enzyme activity or excessive chromogen development (general IHC practice).	Use the no primary control to locate background, then review blocking, washes, antibody concentration and development time (general IHC practice).
An IF/ICC result is used to justify the IHC compartment call.	HPA supplies no DAZL ICC-IF images or main subcellular location (HPA: subcellular); its reported testis pattern comes from tissue IHC (HPA: testis IHC).	Evaluate the paraffin section against the HPA testis IHC pattern and the stage dependent UniProt localisation; assess IF/ICC evidence separately (HPA: tissue IHC; UniProt Q92904).

Source: UniProt Q92904 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing DAZL staining

IHC analysis of DAZL using anti-DAZL antibody (A02069-2). DAZL was detected in paraffin-embedded section of human testies cancer tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1μg/ml rabbit anti-DAZL Antibody (A02069-2) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A02069-2 · IHCIHC analysis of DAZL using anti-DAZL antibody (A02069-2). DAZL was detected in paraffin-embedded section of human testies cancer tissue. Hea

IHC analysis of DAZL using anti-DAZL antibody (A02069-2). DAZL was detected in paraffin-embedded section of mouse testies cancer tissue. Heat mediated antigen retrieval was performed in EDTA buffer (pH8.0, epitope retrieval solution). The tissue section was blocked with 10% goat serum. The tissue section was then incubated with 1μg/ml rabbit anti-DAZL Antibody (A02069-2) overnight at 4°C. Biotinylated goat anti-rabbit IgG was used as secondary antibody and incubated for 30 minutes at 37°C. The tissue section was developed using Strepavidin-Biotin-Complex (SABC) (Catalog # SA1022) with DAB as the chromogen.

A02069-2 · IHCIHC analysis of DAZL using anti-DAZL antibody (A02069-2). DAZL was detected in paraffin-embedded section of mouse testies cancer tissue. Hea

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000092345-DAZL/tissue/cerebral+cortex#imid_21043507

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000092345-DAZL/tissue/colon#imid_21043441

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000092345-DAZL/tissue/liver#imid_21043434

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000092345-DAZL/tissue/kidney#imid_21043443

← swipe / scroll for more images →

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

Sample controls for DAZL IHC & IF

🧪Run testis first: pachytene spermatocytes should stain strongly (HPA: High in testis pachytene spermatocytes). Run adipose tissue as a negative, since adipocytes are not detected there (HPA: Not detected in adipocytes); on the testis slide, use morphologically identified non-pachytene cells as internal background comparators, with a negative result showing no specific chromogen above the no-primary control (textbook IHC control practice).

Positive control tissue: Testis (Pachytene spermatocytes, 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 DAZL; derive a cell-line control from the positive tissue's cell type (Pachytene spermatocytes) and confirm it by RNA or western blot first.

Technical controls: Include no-primary/secondary-only and concentration-matched rabbit IgG isotype controls, plus DAZL knockout material or immunizing-peptide competition if available (caption: rabbit anti-DAZL; textbook IHC specificity controls). Quench endogenous peroxidase and check for endogenous biotin background in testis sections when using the reported biotinylated secondary and SABC–DAB detection (caption: biotinylated goat anti-rabbit IgG, SABC and DAB; textbook IHC practice).

⚠️Feasibility: No DAZL-specific fixation window or fixation effect is reported; the selected A02069-2 paraffin-section caption does not state a fixative, so fixation is unconfirmed (caption: fixative not stated). Heat retrieval in EDTA at pH 8.0 was used in the reported IHC example, but whether staining depends on that retrieval is unreported (caption: heat-mediated EDTA retrieval). The supplied evidence does not establish whether frozen sections or IF are easier; in testis, interpret apparent nuclear versus cytoplasmic staining with germ-cell stage in mind (HPA: no ICC-IF images; UniProt Q92904: stage-dependent localization). The selected A02069-2 tissue-IHC caption documents paraffin sections, but does not specify the fixative (selected-SKU IHC image A02069-2).

HPA tissue IHC evidence for DAZL

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
Testis	Pachytene spermatocytes	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 →
Appendix	Glandular cells	Not detected	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	Not detected	Protein (IHC)	HPA →
Breast	Adipocytes	Not detected	Protein (IHC)	HPA →

Section 3

Advanced DAZL IHC Tips

Use the catalog antibody’s paraffin section evidence and cell resolved testis controls to troubleshoot DAZL staining (datasheet A02069-2; HPA tissue IHC).

What should I adjust if DAZL staining is weak after antigen retrieval?

Start with heat mediated retrieval in EDTA at pH 8.0 (datasheet A02069-2). The documented paraffin section workflow then used 10% goat serum, 1 μg/ml primary antibody overnight at 4°C, and biotinylated secondary antibody for 30 minutes at 37°C (datasheet A02069-2). Check retrieval heating, cooling, and section adherence before changing several conditions together (standard IHC practice). Use testis containing pachytene spermatocytes as a positive control and compare the same cell population across runs (HPA tissue IHC). Record retrieval conditions alongside staining intensity so weak signal can be traced to processing or detection (standard IHC practice).

Can fixation explain weak or variable DAZL staining in paraffin sections?

Target specific fixation sensitivity is unknown: the selected paraffin section caption does not state a fixative (datasheet A02069-2). Record the fixative, fixation duration, and processing history for each specimen, and compare sections processed together before attributing differences to DAZL abundance (standard IHC practice). Keep retrieval at EDTA pH 8.0 and the primary antibody at the documented 1 μg/ml while assessing fixation as a variable (datasheet A02069-2). Include testis with pachytene spermatocytes as a reference for the expected positive cell population (HPA tissue IHC). Uneven staining within a section should also prompt inspection of section quality and reagent coverage (standard IHC practice).

How should I evaluate nuclear versus cytoplasmic DAZL staining?

Assess compartment and germ cell stage together: DAZL is predominantly cytoplasmic, with nuclear localisation in spermatogonia until near the end of meiotic prophase and cytoplasmic localisation thereafter (UniProt Q92904 subcellular). In paraffin sections, use the counterstain and tissue architecture to score nuclear and cytoplasmic signal separately within identifiable cells (standard IHC practice). Strong staining in pachytene spermatocytes provides a cell resolved reference, but does not establish that every stained nucleus or cytoplasm is specific (HPA tissue IHC; standard IHC practice). Check whether the pattern persists across intact regions and disappears in the no primary control (standard IHC practice). Document mixed patterns without assigning a developmental stage from DAZL staining alone (standard IHC practice).

Could epitope choice explain disagreement between DAZL staining results?

DAZL has 2 listed isoforms, an RRM at residues 40–115, and a DAZ region at 167–190 (UniProt Q92904 isoforms and domains). An antibody’s epitope must be known before staining can be assigned to either isoform or a particular domain (standard IHC practice). The supplied paraffin section caption documents staining conditions but gives no epitope location or isoform specificity for A02069-2 (datasheet A02069-2). UniProt also lists phosphotyrosine at residue 276; this record alone does not establish an effect on this antibody’s staining (UniProt Q92904 modified residues; standard IHC practice). When results disagree, compare antibody epitope documentation and section controls before making isoform claims (standard IHC practice).

How should I plan IF follow up to a chromogenic DAZL result?

Treat IF as a separate validation task: the supplied A02069-2 image documents chromogenic staining in paraffin sections, while the HPA subcellular payload lists no ICC/IF images (datasheet A02069-2; HPA subcellular). Multiplex DAZL with an independently validated marker of the expected pachytene spermatocyte population and use single stain controls to assess channel separation (HPA tissue IHC; standard IF practice). Choose fluorophores, including a longer wavelength option, after checking tissue autofluorescence and filter overlap (standard IF practice). Because DAZL is intracellular and has no transmembrane segment, assess permeabilisation for access to cytoplasmic and nuclear epitopes (UniProt Q92904 subcellular and topology; standard IF practice). Keep IF optimisation on its dedicated guide page (application scope).

What should I check when DAZL IHC shows diffuse background?

First compare an intact testis section with a no primary control and inspect whether staining tracks tissue edges, folds, or damaged regions (HPA tissue IHC; standard IHC practice). The documented workflow used 10% goat serum, a biotinylated secondary antibody, a streptavidin–biotin complex, and DAB, so each detection step deserves a matched control when background is high (datasheet A02069-2; standard IHC practice). Apply a peroxidase block and assess endogenous biotin interference as general controls for this detection chemistry (standard IHC practice). Check washing and reagent coverage before changing the documented 1 μg/ml primary concentration (datasheet A02069-2; standard IHC practice). Score only intact cells with interpretable compartment boundaries (standard IHC practice).

How can I quantify DAZL staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population before scoring: HPA reports high DAZL staining in pachytene spermatocytes in testis (HPA tissue IHC). Report the percentage of positive cells and an H-score for that population, or positive cell density per mm² of evaluable tissue when cell counts are the study endpoint (standard IHC practice). Normalise positive counts to the number of eligible cells, and normalise density to measured evaluable area rather than total slide area (standard IHC practice). Keep retrieval at EDTA pH 8.0 and detection settings consistent across compared sections (datasheet A02069-2; standard IHC practice). Record nuclear and cytoplasmic scores separately when localisation is relevant (UniProt Q92904 subcellular; standard IHC practice).

Which staining patterns support a specific DAZL IHC result?

A convincing result places signal in morphologically identifiable germ cells, with strong staining in pachytene spermatocytes as a reference pattern (HPA tissue IHC; standard IHC practice). Interpret cytoplasmic staining alongside the reported stage dependent nuclear localisation, rather than rejecting every nuclear signal outright (UniProt Q92904 subcellular). Diffuse staining in the wrong cell population, abrupt edge staining, and signal confined to necrotic or damaged areas warrant review against section morphology and a no primary control (standard IHC practice). Persistent DAB signal in that control should trigger a check of endogenous peroxidase and detection reagent background (standard IHC practice). A single positive compartment does not establish isoform identity because 2 isoforms are listed without antibody epitope mapping here (UniProt Q92904 isoforms; datasheet A02069-2).

Boster reagents

Best DAZL / Deleted in azoospermia-like IHC Antibodies

A02069-2 has real IHC data from paraffin sections of human, mouse and rat testis cancer tissue (catalog image captions); IF/ICC data are not provided (catalog payload).

Real IHC data

Anti-DAZL ® Antibody

Cat # A02069-2

View product →

A02069-2 is listed for IHC in human, mouse and rat samples (catalog applications and reactivity). Its image captions show staining of paraffin sections of human, mouse and rat testis cancer tissue; no IF figure is listed (catalog image captions; catalog IF images).

Which to pick: For tissue IHC across human, mouse and rat samples, choose A02069-2: it is IHC listed, rabbit hosted and shown on paraffin sections from all three species (catalog applications, host and image captions). Its captions do not report the fixative (catalog image captions). No IF/ICC choice is supported by the supplied application list or figures, and the antibody’s clonality is unreported (catalog applications, IF images and clone field).

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

References

UniProt Consortium. UniProt entry Q92904 (DAZL_HUMAN, Deleted in azoospermia-like).
Human Protein Atlas. DAZL tissue IHC expression (reliability: Enhanced).
Human Protein Atlas. DAZL subcellular location (ICC-IF): Highest expression in HAP1: 17.2 nTPM.
Human Protein Atlas. DAZL antibody validation summary (2 antibodies).
Suppressing Dazl modulates tumorigenicity and stemness in human glioblastoma cells. BMC cancer 2020 — PMC7368788.
RNA immunoprecipitation identifies novel targets of DAZL in human foetal ovary. Molecular human reproduction 2017 — PMC5943682.
GDF9 is transiently expressed in oocytes before follicle formation in the human fetal ovary and is regulated by a novel NOBOX transcript. PloS one 2015 — PMC4366263.
Single-cell RNA sequencing of mitotic-arrested prospermatogonia with DAZL::GFP chickens and revealing unique epigenetic reprogramming of chickens. Journal of animal science and biotechnology 2022 — PMC9169296.
PubMed PMID:8896558 — UniProt-cited evidence.
PubMed PMID:8968755 — UniProt-cited evidence.
PubMed PMID:8968756 — UniProt-cited evidence.