PDRG1 / p53 and DNA damage-regulated protein 1 · IHC design guide

Design Immunohistochemistry for PDRG1

Plan PDRG1 staining in paraffin sections using the reported cytoplasmic pattern, especially in Leydig cells (HPA tissue IHC). This guide covers fixation consistency, controls and chromogenic scoring.

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

Immunohistochemistry protocol sheet for PDRG1 (IHC for PDRG1): expected localisation Cytoplasmic staining in several tissues (HPA tissue IHC), antibody A13826, validated IHC image, and IHC protocol steps — Printable **PDRG1** IHC protocol sheet — expected localisation Cytoplasmic staining in several tissues (HPA tissue IHC), antibody A13826, controls and protocol steps. Open the full PDRG1 IHC guide →

Navigate to: Protocols Staining pattern Controls Antibodies

PDRG1 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 staining in several tissues (HPA tissue IHC)
	Staining pattern	Cytoplasmic staining, strongest in Leydig cells (HPA tissue IHC)
	Antigen retrieval	Tris-EDTA pH 8.0 HIER, heat-mediated (datasheet A13826)
	Positive control ⓘ	Testis+4 more · see all
	Negative control ⓘ	Adipose tissue+4 more · see all

Important caveats

Reasons your staining may differ from the expected pattern.

	Fixation	Keep fixation consistent across sections (standard IHC practice; not target-specific)
	Caveat	Staining has medium RNA concordance; verify the pattern (HPA tissue IHC)
	Regulation	Expression predominates in normal testis (UniProt)
	Isoform / epitope	One 1–133 chain; no annotated isoforms (UniProt)

Section 1

Recommended PDRG1 IHC & IF Protocols

Compare the catalog antibody’s IHC-P protocol (datasheet A13826) with a published PDRG1 IHC protocol (PMC13050440 methods).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded Human brain tissue; fixative not specified (datasheet A13826)
Fixation	Image fixative and duration unreported (datasheet A13826); verify before use.
Sectioning	4–5 µm sections on charged slides (standard)
Deparaffinisation	Xylene, graded ethanol series to water (standard)
Antigen retrieval	Heat retrieval: Tris-EDTA pH 8.0 (datasheet A13826); 20 min, 95–100 °C (standard)
Peroxidase block	3% H2O2, 10 min, room temperature (standard)
Blocking	10% normal serum of the secondary host, 30 min, room temperature (standard)
Primary antibody	Rabbit anti-PDRG1, 1:100-1:300 (datasheet A13826)
Primary incubation	Overnight at 4 °C (standard)
Detection	HRP-polymer secondary, DAB chromogen 5–10 min (standard)
Counterstain	Hematoxylin, blue, dehydrate and mount (standard)
Expected result	PDRG1-positive staining in leydig cells of testis (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression in several tissues, mainly in Leydig cells. No signal in the no-primary control.

💡Decision noteStart with heat-mediated Tris-EDTA pH 8.0 for the catalog antibody (datasheet A13826); consider citrate pH 6.0 when adapting the published protocol (PMC13050440 methods).

Section 2

What Is the Expected PDRG1 Staining Pattern?

PDRG1 is cytoplasmic and has no transmembrane segment (UniProt Q9NUG6). In tissue IHC, expect cytoplasmic staining in several tissues, strongest in testicular Leydig cells (HPA tissue IHC: High in Leydig cells). The HPA tissue profile is Approved, with medium consistency between staining and RNA data, and awaits external verification (HPA tissue IHC: reliability).

What am I looking at on my slide?
Distinct cytoplasmic staining in testicular Leydig cells, with weaker staining in some other cell populations.	This fits the strongest reported tissue result: High in Leydig cells (HPA tissue IHC). Medium staining also occurs in adrenal glandular cells, bronchial respiratory epithelial cells, and cerebellar Purkinje cells (HPA tissue IHC). Compare the named cell population, rather than treating an entire organ as uniformly positive.
Signal appears predominantly nuclear, membranous, or extracellular, without a convincing cytoplasmic component.	That distribution conflicts with the cytoplasmic tissue profile (HPA tissue IHC) and UniProt localisation and topology (UniProt Q9NUG6). Check morphology, counterstain, detection background, and antibody specificity before interpreting it as PDRG1. The ICC-IF actin-filament report is a separate observation (HPA subcellular ICC-IF).
Strong staining appears in a cell population reported as Not detected, such as adipocytes or liver cholangiocytes.	That result warrants scrutiny, especially beside a correctly stained positive section (HPA tissue IHC: Not detected in these populations). Cross-reactivity or endogenous detection activity may explain it (standard IHC practice). An HPA Not detected result is a sampled staining observation, not proof of universal absence.
Diffuse colour covers stroma, blank regions, and multiple cell types without clear cellular boundaries.	An unstructured pattern cannot establish the reported cytoplasmic localisation (HPA tissue IHC). Review the no-primary control, blocking, washes, and chromogen development for nonspecific or endogenous signal (standard IHC practice). Judge any remaining staining against intact cells and the expected positive population.
No convincing staining appears in testicular Leydig cells.	This conflicts with the reported High Leydig-cell signal (HPA tissue IHC). Confirm that Leydig cells are present and identifiable, then review the IHC-validated antibody, antigen retrieval, detection reagents, and a positive control (standard IHC practice). HPA's Approved rating still has medium consistency and pending external verification (HPA tissue IHC).

💡Expected PDRG1 appearanceA convincing positive is distinct cytoplasmic staining in testicular Leydig cells at the reported High level (HPA tissue IHC); dominant nuclear, membranous, or structureless staining needs investigation against that pattern (UniProt Q9NUG6; standard IHC practice).

How each factor affects the staining
Tissue and cell selection	Testicular Leydig cells provide the clearest reported positive comparison (HPA tissue IHC: High). Adipocytes and bone-marrow hematopoietic cells were Not detected in the cited profile (HPA tissue IHC); use their results as context, not absolute negative standards.
Compartment and molecular topology	UniProt places PDRG1 in the cytoplasm and reports no transmembrane segment (UniProt Q9NUG6). Interpret chromogenic signal within cell boundaries; dominant membrane staining lacks support from the supplied localisation evidence.
Strength of tissue evidence	The tissue profile is Approved, but staining and RNA show medium consistency, with external verification pending (HPA tissue IHC). HPA047084 has Approved IHC status; the supplied record does not report IHC Enhanced validation (HPA antibodies).
IF/ICC pattern?	For IF/ICC interpretation, HPA reports actin-filament localisation using an ICC-Approved antibody, HPA063542 (HPA subcellular ICC-IF; HPA antibodies). This differs in resolution and assay from cytoplasmic tissue IHC; it does not establish an IHC-P protocol or require filament resolution on a chromogenic section.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
The Leydig-cell positive control is blank.	A failed staining run or missing target cell population is possible (standard IHC practice); High Leydig-cell staining is reported (HPA tissue IHC).	Verify cell identity on the section, then check antibody application, retrieval conditions, detection reagents, and run controls (standard IHC practice). Record the result as inconclusive until the positive control works.
Signal is widespread in cells reported as Not detected.	Nonspecific antibody binding or endogenous detection activity may contribute (standard IHC practice); HPA lists selected populations as Not detected (HPA tissue IHC).	Compare a no-primary control and a known positive section; inspect whether the same signal appears without primary antibody (standard IHC practice). Reassess specificity before calling those cells PDRG1-positive.
Only nuclei or cell borders stain strongly.	The dominant compartment disagrees with cytoplasmic PDRG1 localisation (UniProt Q9NUG6; HPA tissue IHC).	Check counterstain and cell boundaries, examine no-primary staining, and repeat with the IHC-validated antibody if needed (standard IHC practice). Score only a supported, cellular pattern.
The whole section has weak, diffuse colour.	Incomplete blocking or washing, or excess detection development, can obscure specific staining (standard IHC practice).	Review controls and reagent timing, then adjust the general IHC workflow as indicated by those controls (standard IHC practice). Reassess Leydig-cell cytoplasm against nearby background (HPA tissue IHC).
A medium-staining tissue gives little or no signal.	Its reported level is below the High Leydig-cell reference; for example, adrenal glandular cells are Medium (HPA tissue IHC).	Check a Leydig-cell positive section in the same run before inferring assay failure (HPA tissue IHC; standard IHC practice). Document the specific cell population and staining threshold.
Tissue IHC lacks visible actin filaments seen in an ICC-IF reference.	HPA reports actin-filament localisation in ICC-IF and broader cytoplasmic staining in tissue IHC (HPA subcellular ICC-IF; HPA tissue IHC).	Judge the chromogenic section by its cytoplasmic cell-level pattern (HPA tissue IHC). Consult the separate IF/ICC guide for filament-level interpretation.

Source: UniProt Q9NUG6 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing PDRG1 staining

Immunohistochemical analysis of paraffin-embedded Human brain. Antibody was diluted at 1:100 (4° overnight). High-pressure and temperature Tris-EDTA, pH8.0 was used for antigen retrieval. Negetive contrl (right) obtaned from antibody was pre-absorbed by immunogen peptide.

A13826 · IHCImmunohistochemical analysis of paraffin-embedded Human brain. Antibody was diluted at 1:100 (4° overnight). High-pressure and temperature T

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000088356-PDRG1/tissue/cerebral+cortex#imid_14591116

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000088356-PDRG1/tissue/colon#imid_14591042

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000088356-PDRG1/tissue/liver#imid_14591043

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000088356-PDRG1/tissue/kidney#imid_14591044

HPA · ICC-IF CACO-2Human Protein Atlas immunofluorescence, CACO-2, antibody HPA063542; green = PDRG1, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for PDRG1 IHC & IF

🧪Run testis first and expect Leydig cells to stain (HPA: High in testis Leydig cells). Use adipose tissue as the negative tissue and expect adipocytes to lack detectable staining (HPA: Not detected in adipocytes); on the testis slide, treat neighboring cells without specific signal as internal negatives without assigning them a target-negative identity.

Positive control tissue: Testis (Leydig cells, HPA High)

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PDRG1 in CACO-2, SiHa, U2OS, with annotated localisation: Actin filaments (approved) (HPA subcellular).

Technical controls: Include a no-primary, secondary-only control and a control immunoglobulin matched to the primary antibody’s host species and, for a monoclonal primary, isotype; use a PDRG1 knockout specimen or an immunogen peptide block as a biological specificity control (A13826 caption: peptide preabsorption used). For chromogenic IHC in testis, block endogenous peroxidase and check pigment against the no-primary slide; for IF, check tissue autofluorescence.

⚠️Feasibility: No supplied source reports a PDRG1-specific fixation window or fixation effect, and the selected A13826 paraffin-section caption does not report a fixative (A13826 caption: fixative unreported). The reported IHC condition uses Tris-EDTA retrieval at pH 8.0, but the caption does not establish that retrieval is required (A13826 caption: high-pressure, high-temperature retrieval). There is no supplied comparison showing that frozen sections or IF are easier; ICC-IF images exist for CACO-2, SiHa and U2OS, with actin filament localization reported (HPA: subcellular ICC-IF).

HPA tissue IHC evidence for PDRG1

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Medium consistency between antibody staining and RNA expression data. Pending external verification.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.

Positive expression · recommended positive controls

Tissue	Cell type	Level	Evidence	Source
Testis	Leydig cells	High	Protein (IHC)	HPA →
Adrenal gland	Glandular cells	Medium	Protein (IHC)	HPA →
Appendix	Glandular 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 →
Bone marrow	Hematopoietic cells	Not detected	Protein (IHC)	HPA →
Caudate	Glial cells	Not detected	Protein (IHC)	HPA →
Cervix	Glandular cells	Not detected	Protein (IHC)	HPA →
Liver	Cholangiocytes	Not detected	Protein (IHC)	HPA →

Section 3

Advanced PDRG1 IHC Tips

Troubleshoot PDRG1 staining in paraffin sections by checking retrieval, cellular localisation and controls before comparing signal across tissues.

What retrieval should I try first if PDRG1 staining is weak?

Use heat-mediated Tris-EDTA antigen retrieval at pH 8.0 first (datasheet A13826). The selected paraffin-section image used high pressure and temperature with this buffer, followed by antibody at 1:100 overnight at 4°C (caption A13826). If staining is weak, check that sections were fully deparaffinised and that the retrieval vessel maintained its intended temperature before changing conditions (standard IHC practice). Run any retrieval comparison on adjacent sections with the same antibody incubation and detection settings, using Leydig cells as a tissue reference where available (HPA: high in testis Leydig cells).

Could fixation explain weak PDRG1 staining in my paraffin sections?

Target-specific fixation sensitivity is unknown from the supplied evidence (caption A13826: fixative not stated). The selected image shows staining in paraffin-embedded human brain after Tris-EDTA retrieval at pH 8.0, but the caption does not identify how that tissue was fixed (caption A13826). Record the actual fixative, fixation duration and processing history for each specimen, then compare similarly handled sections using the same retrieval and 1:100 antibody dilution as a starting condition (caption A13826; standard IHC practice). If signal varies with processing history, test matched sections and controls before attributing the difference to PDRG1 abundance (standard IHC practice).

How should I assess nuclear or filament-like staining for PDRG1?

Assess cytoplasmic staining first because UniProt places PDRG1 in the cytoplasm, while tissue IHC reports mainly cytoplasmic expression in Leydig cells (UniProt Q9NUG6 subcellular location; HPA tissue IHC). HPA cellular imaging also assigns PDRG1 to actin filaments, so a filament-like pattern is plausible but should be checked in the relevant tissue and assay (HPA subcellular: approved actin filaments). Score nuclear-only chromogen separately from cytoplasmic signal and compare it with a no-primary control on an adjacent section (standard IHC practice). Do not classify nuclear-only staining as confirmed PDRG1 localisation from these sources alone (UniProt Q9NUG6 subcellular location; HPA tissue IHC).

Could an isoform or modified epitope explain inconsistent PDRG1 staining?

The supplied record lists one 1–133 chain, no annotated isoforms, no glycosylation sites and no modified residues for PDRG1 (UniProt Q9NUG6 processing, isoforms and modifications). It also lists no transmembrane segment or signal peptide, so a membrane-facing epitope is not supported by this record (UniProt Q9NUG6 topology and processing). Those annotations do not establish where the catalog antibody binds or whether its epitope survives tissue processing (UniProt Q9NUG6; caption A13826). For discordant sections, compare retrieval on adjacent cuts and include the documented immunogen-peptide preabsorption control when available; interpret loss of staining alongside tissue morphology (caption A13826; standard IHC practice).

How can I check PDRG1 localisation with multiplex immunofluorescence?

For a complementary IF experiment, pair PDRG1 with a validated marker of the expected cell population, such as Leydig cells in testis, and inspect whether their signals occupy the same cells (HPA tissue IHC: high in Leydig cells; standard IF practice). Choose fluorophores after measuring tissue autofluorescence in an unstained section, and include single-colour controls to assess bleed-through (standard IF practice). Because PDRG1 has no annotated transmembrane segment and is reported in the cytoplasm, use permeabilisation appropriate for an intracellular epitope, then optimise it empirically for the antibody (UniProt Q9NUG6 topology and subcellular location; standard IF practice). The paraffin-section IHC caption supplies no IF fixation or permeabilisation condition (caption A13826).

How do I distinguish PDRG1 signal from chromogenic background?

Check a no-primary section for nonspecific detection and a section with peroxidase blocking for enzyme-driven chromogen deposition (standard chromogenic IHC practice). The selected image includes an immunogen-peptide preabsorbed negative control, which can help assess antibody-dependent staining under that image's conditions (caption A13826). If diffuse colour persists, review deparaffinisation, blocking, wash steps and DAB development while keeping retrieval at pH 8.0 for the initial comparison (standard IHC practice; datasheet A13826). Compare cytoplasmic staining within intact cells against the controls, especially where tissue edges or damaged regions accumulate colour (UniProt Q9NUG6 subcellular location; standard IHC practice).

What is a defensible way to quantify PDRG1 tissue IHC? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and scoring compartment before measuring chromogen; cytoplasmic staining is the supported tissue pattern (HPA tissue IHC; UniProt Q9NUG6 subcellular location). Within each annotated population, report the percentage of positive cells and an H-score based on staining intensity, with the number of evaluable cells or tissue area recorded for each section (standard IHC practice). Normalise cell counts to the same cell population or area in mm², and keep exposure, DAB development and scoring thresholds consistent across the comparison (standard IHC practice). Report testis Leydig cells separately from other tissue populations because their reported staining levels differ (HPA tissue IHC: high in Leydig cells).

When should an apparent PDRG1-positive area be treated cautiously?

Give greatest weight to staining in intact cytoplasm within an identified cell population, consistent with the reported PDRG1 tissue pattern (UniProt Q9NUG6 subcellular location; HPA tissue IHC). Treat nuclear-only colour, staining confined to section edges or necrotic areas, and colour retained in a no-primary or peroxidase-control section as possible artefacts requiring review (standard chromogenic IHC practice). Cell identity matters: HPA reports high staining in testis Leydig cells but no detection in adipocytes, so an unexpected population needs its own control and morphology check (HPA tissue IHC). Even a convincing pattern is provisional because the HPA tissue assessment has medium staining-to-RNA consistency and awaits external verification (HPA: Approved reliability description).

Boster reagents

Best PDRG1 / p53 and DNA damage-regulated protein 1 IHC Antibodies

A13826 has a human paraffin-section IHC image (A13826 IHC caption) and is listed for IF and for human, mouse, and rat reactivity (catalog: applications/reactivity).

Real IHC data Immunohistochemical analysis of paraffin-embedded Human brain. Antibody was diluted at 1:100 (4° overnight). High-pressure and temperature Tris-EDTA, pH8.0 was used for antigen retrieval. Negetive contrl (right) obtaned from antibody was pre-absorbed by immunogen peptide.

Anti-PDRG1/Pdrg Antibody

Cat # A13826

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A13826 will render with an IHC image of human paraffin-embedded brain, stained at 1:100 after Tris-EDTA retrieval at pH 8.0 (A13826 IHC caption). IF is listed as an application, but no IF image is supplied (catalog: applications; A13826 IF image alts).

Which to pick: For tissue IHC, choose A13826 based on its own human paraffin-section image; the fixative is unreported (A13826 IHC caption). For IF, A13826 is a listed rabbit polyclonal antibody with a catalog dilution of 1:50; ICC-specific validation is unreported (catalog: host/applications/if_dilution). For cross-species work, A13826 lists human, mouse, and rat reactivity, while its displayed IHC evidence is limited to human tissue (catalog: reactivity; A13826 IHC caption).

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

References

UniProt Consortium. UniProt entry Q9NUG6 (PDRG1_HUMAN, p53 and DNA damage-regulated protein 1).
Human Protein Atlas. PDRG1 tissue IHC expression (reliability: Approved).
Human Protein Atlas. PDRG1 subcellular location (ICC-IF): Localized to the actin filaments..
Human Protein Atlas. PDRG1 antibody validation summary (2 antibodies).
Identification of a Novel PDRG1-EZH2-p21 Pathway Controlling Senescence and Tumor Progression in Hepatocellular Carcinoma. International journal of biological sciences 2026 — PMC13050440.
PubMed PMID:14562055 — UniProt-cited evidence.
PubMed PMID:14702039 — UniProt-cited evidence.
PubMed PMID:11780052 — UniProt-cited evidence.