PRCP / Lysosomal Pro-X carboxypeptidase · IHC design guide

Design Immunohistochemistry for PRCP

Plan PRCP staining in paraffin sections around the granular cytoplasmic pattern observed in tissues (HPA tissue IHC). Kidney tubules offer a high-staining reference (HPA tissue IHC), but staining intensity needs cautious interpretation because antibody staining and RNA expression show low consistency (HPA tissue IHC).

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

Immunohistochemistry protocol sheet for PRCP (IHC for PRCP): expected localisation Granular cytoplasm observed (HPA tissue IHC); lysosome expected (UniProt), antibody A04829-1, validated IHC image, and IHC protocol steps — Printable **PRCP** IHC protocol sheet — expected localisation Granular cytoplasm observed (HPA tissue IHC); lysosome expected (UniProt), antibody A04829-1, controls and protocol steps. Open the full PRCP IHC guide →

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PRCP 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	Granular cytoplasm observed (HPA tissue IHC); lysosome expected (UniProt)
	Staining pattern	Granular cytoplasm in most tissues; high in kidney tubules (HPA tissue IHC)
	Antigen retrieval	Tris-EDTA pH 9.0 HIER, heat-mediated (datasheet A04829-1)
	Positive control ⓘ	Adrenal gland+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 and RNA show low consistency; verify independently (HPA tissue IHC)
	Regulation	Staining-linked regulation unspecified (UniProt)
	Isoform / epitope	2 isoforms; mature chain 46–496; epitope map unknown (UniProt)

Section 1

Recommended PRCP IHC & IF Protocols

The catalog antibody IHC-P protocol is followed by published PRCP staining protocols from three articles (PMC6180013; PMC5567309; PMC9639567).

Recommended immunohistochemistry (IHC-P) protocol parameters
Sample	Paraffin-embedded human Squamous cell carcinoma of lung tissue; fixative not specified (datasheet A04829-1)
Fixation	Image fixative and duration unreported (datasheet A04829-1); verify before use.
Sectioning	4–5 µm sections on charged slides (standard)
Deparaffinisation	Xylene, graded ethanol series to water (standard)
Antigen retrieval	Heat retrieval: Tris-EDTA pH 9.0 (datasheet A04829-1); 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-PRCP, 1:50 recommended; image 1:200 (datasheet A04829-1)
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	PRCP-positive staining in glandular cells of adrenal gland (HPA tissue IHC: High). HPA tissue profile: Cytoplasmic expression with a granular pattern in most tissues. No signal in the no-primary control.

💡Decision noteStart with Tris-EDTA pH 9.0 heat retrieval (datasheet A04829-1); consider sodium citrate pH 6 for the endarterectomy or aortic root method (PMC6180013).

Section 2

What Is the Expected PRCP Staining Pattern?

PRCP is a lysosomal protein with no transmembrane segment (UniProt P42785). In paraffin tissue sections, expect granular cytoplasmic staining, especially in adrenal glandular cells, kidney tubule cells, splenic red pulp cells and cerebellar molecular-layer cells (HPA: High in each; granular cytoplasmic pattern in most tissues). Interpret intensity cautiously: HPA rates the tissue IHC profile Approved but reports low agreement with RNA expression and pending external verification (HPA: reliability description).

What am I looking at on my slide?
Granular cytoplasmic signal in kidney tubule cells or adrenal glandular cells.	This fits the reported distribution (HPA: High in both cell populations; granular cytoplasmic pattern). Score the specified cells and their intracellular pattern together; staining anywhere in a positive tissue alone does not establish specificity (standard IHC practice).
Predominantly nuclear, sharply membranous or uniform extracellular staining.	These compartments do not match the expected granular cytoplasm (HPA: tissue IHC profile) or lysosomal localisation (UniProt P42785). Treat an isolated wrong-compartment signal as suspect; review controls and antibody localisation before calling it PRCP (standard IHC practice).
Strong staining in adipocytes, bronchial respiratory epithelium or bone-marrow hematopoietic cells.	Those specific populations are reported as Not detected (HPA: tissue IHC). Check morphology and controls; staining may reflect cross-reactivity or chromogenic detection background rather than demonstrated PRCP expression (standard IHC practice).
Diffuse colour across cells and surrounding tissue, with little cell-specific granularity.	That appearance obscures the reported granular cytoplasmic pattern (HPA: tissue IHC profile). Compare a no-primary control and review blocking, washing and chromogen development; these are general IHC background checks, not documented PRCP-specific effects (standard IHC practice).
No signal in an otherwise interpretable kidney tubule or adrenal glandular positive control.	Both cell populations are reported High (HPA: tissue IHC), so absence raises a technical concern. Check that the control tissue contains the relevant cells and that primary antibody, retrieval and detection steps worked (standard IHC practice); HPA does not establish PRCP-specific fixation sensitivity.

💡Expected PRCP appearanceCall a result supportive when the relevant cells show distinct granular cytoplasmic staining, strongest in HPA High populations such as kidney tubules or adrenal glandular cells (HPA: tissue IHC); dominant nuclear, membranous or diffuse tissue-wide colour is suspect given the reported pattern (HPA: granular cytoplasm; UniProt P42785: lysosome).

How each factor affects the staining
Cell population and reference intensity	Use cell-level comparators: kidney tubules, adrenal glandular cells, splenic red pulp cells and cerebellar molecular-layer cells are High; breast myoepithelial cells and cortical glia are Medium (HPA: tissue IHC). A low or negative call for one cell population cannot be generalized to every cell in its tissue.
IHC evidence strength	The tissue profile is Approved, while agreement between staining and RNA is low and external verification is pending (HPA: reliability description). One antibody has IHC Approved status; the separate ICC antibody has ICC Supported status (HPA: antibody validation). Interpret unexpected strong staining with independent controls.
Processing and epitope position	PRCP has a signal peptide at residues 1–21, a propeptide at 22–45 and a mature chain at 46–496 (UniProt P42785). If the catalog antibody's epitope is known, compare its position with these regions; the supplied record gives no epitope, so it cannot predict that antibody's staining of processed protein.
IF/ICC Q&A: what localisation is expected?	Supported vesicular staining is reported in U2OS ICC-IF images (HPA: subcellular profile). That supports an intracellular punctate interpretation alongside UniProt's lysosomal annotation (UniProt P42785); it does not establish that every fluorescent punctum is a lysosome or supply an IF/ICC protocol.
Retrieval and detection choices	No PRCP-specific retrieval condition or dilution is supplied. For paraffin chromogenic IHC, follow the catalog antibody's validated IHC-P directions and include suitable controls when optimizing retrieval and detection (standard IHC practice); do not infer a PRCP fixation effect from HPA staining levels.

Why is my staining missing, weak or wrong?
Situation	Likely cause	Next action
Positive control has no detectable granular cytoplasmic stain.	A missing target-cell population or a failed antibody, retrieval or detection step is possible (HPA: High in kidney tubules and adrenal glandular cells; standard IHC practice).	Confirm the relevant cells are present, then check the catalog antibody's IHC-P directions, reagent performance and positive control on the same run (standard IHC practice).
Colour persists in a no-primary control.	Primary-independent chromogenic activity or nonspecific detection background is possible (standard IHC practice). This control cannot identify PRCP expression.	Review endogenous enzyme blocking where applicable, secondary detection, washes and chromogen timing; repeat the no-primary control alongside tissue sections (standard IHC practice).
Strong nuclear or cell-surface signal dominates.	The compartment conflicts with granular cytoplasmic tissue staining and lysosomal annotation (HPA: tissue IHC; UniProt P42785).	Check tissue morphology and control slides, then reassess antibody specificity before scoring the signal as PRCP (standard IHC practice).
Adipocytes or bronchial epithelial cells stain strongly.	Those populations are Not detected in the reference profile (HPA: tissue IHC); cross-reactivity or detection background is possible (standard IHC practice).	Compare the same run's positive and no-primary controls, and record the discrepancy at cell level rather than reclassifying the entire tissue (standard IHC practice).
Only diffuse weak colour is visible in a positive tissue.	Weak diffuse colour is difficult to distinguish from background and lacks the reported granularity (HPA: tissue IHC profile).	Inspect a matched negative control, optimize routine washing and development, and score only reproducible cell-associated staining (standard IHC practice).
IHC and ICC-IF seem to give different compartments.	HPA reports granular cytoplasm in tissue IHC and supported vesicles in ICC-IF; these descriptions are compatible at different viewing scales (HPA: tissue and subcellular profiles).	Compare intracellular localisation within each preparation and use its own controls; do not transfer an ICC-IF validation status or protocol to paraffin IHC (HPA: antibody validation; standard IHC practice).

Source: UniProt P42785 Human Protein Atlas tissue Human Protein Atlas subcellular

Experiment evidence

IHC & IF images showing PRCP staining

Immunohistochemical analysis of paraffin-embedded human Squamous cell carcinoma of lung. 1, Antibody was diluted at 1:200 (4° overnight). 2, Tris-EDTA, pH9.0 was used for antigen retrieval. 3, Secondary antibody was diluted at 1:200 (room temperature, 45min).

A04829-1 · IHCImmunohistochemical analysis of paraffin-embedded human Squamous cell carcinoma of lung. 1, Antibody was diluted at 1:200 (4° overnight). 2,

HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000137509-PRCP/tissue/cerebral+cortex#imid_4477956

HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000137509-PRCP/tissue/colon#imid_4477882

HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000137509-PRCP/tissue/liver#imid_4477883

HPA · KidneyHuman Protein Atlas IHC, Kidney. Source: https://www.proteinatlas.org/ENSG00000137509-PRCP/tissue/kidney#imid_4477884

HPA · ICC-IF U2OSHuman Protein Atlas immunofluorescence, U2OS, antibody HPA071115; green = PRCP, blue = nucleus, red = microtubules.

← swipe / scroll for more images →

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

Sample controls for PRCP IHC & IF

🧪Run kidney first and expect staining in tubular cells (HPA: High in kidney tubular cells). Use adipose tissue as the negative comparator, with adipocytes expected to lack detectable staining (HPA: Not detected in adipocytes); on the kidney slide, compare tubular staining with neighboring cells that lack specific signal, without assuming those cells are validated PRCP negatives.

Positive control tissue: Adrenal gland (Glandular cells, HPA High)

Negative control tissue: Adipose tissue (HPA Not detected)

ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show PRCP in U2OS, with annotated localisation: Vesicles (supported) (HPA subcellular).

Technical controls: Include a no-primary, secondary-only control and a host-species- and clonality-matched isotype control, then confirm specificity with PRCP knockout tissue or peptide blocking if the immunizing peptide is available (standard IHC practice). For kidney chromogenic IHC, block endogenous peroxidase and check endogenous biotin if using biotin-based detection (standard IHC practice).

⚠️Feasibility: A target-specific fixation window or fixation effect is unreported in the supplied evidence; the selected A04829-1 paraffin-section caption also leaves the fixative unreported (selected-SKU caption: fixative not stated). The caption uses Tris-EDTA retrieval at pH 9.0 and primary antibody at 1:200 overnight at 4°C, but does not establish whether retrieval is essential (selected-SKU caption). Frozen sections cannot be judged easier from these data; ICC-IF has supported vesicular localization in U2OS, while kidney tubules warrant attention to endogenous biotin if biotin-based detection is used (HPA: Vesicles, U2OS; standard IHC practice).

HPA tissue IHC evidence for PRCP

Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Approved — Low 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
Adrenal gland	Glandular cells	High	Protein (IHC)	HPA →
Cerebellum	Cells in molecular layer	High	Protein (IHC)	HPA →
Kidney	Cells in tubules	High	Protein (IHC)	HPA →
Spleen	Cells in red pulp	High	Protein (IHC)	HPA →
Breast	Myoepithelial cells	Medium	Protein (IHC)	HPA →

Undetected expression · recommended negative controls

Tissue	Cell type	Level	Evidence	Source
Adipose tissue	Adipocytes	Not detected	Protein (IHC)	HPA →
Appendix	Glandular cells	Not detected	Protein (IHC)	HPA →
Bone marrow	Hematopoietic cells	Not detected	Protein (IHC)	HPA →
Bronchus	Respiratory epithelial cells	Not detected	Protein (IHC)	HPA →
Cervix	Glandular cells	Not detected	Protein (IHC)	HPA →

Section 3

Advanced PRCP IHC Tips

Troubleshoot PRCP staining in paraffin sections by checking retrieval, compartment, controls and scoring before interpreting chromogenic signal.

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

Start with heat-mediated Tris-EDTA antigen retrieval at pH 9.0 for paraffin-section IHC (datasheet A04829-1). The selected tissue image used that buffer before staining with the catalog antibody at 1:200, incubated at 4°C overnight (caption A04829-1). Keep section thickness, heating and cooling consistent across test and control slides so retrieval is the main variable (standard IHC practice). If staining remains weak, compare a gentler retrieval condition on adjacent sections while checking for tissue damage and nonspecific staining (standard IHC practice). A granular cytoplasmic pattern is a useful readout, although it cannot establish specificity by itself (HPA tissue IHC).

Could fixation explain weak or uneven PRCP staining?

The selected paraffin-section caption does not state the fixative, so PRCP-specific fixation sensitivity is unknown (caption A04829-1). Record the fixative and processing history for each specimen, then compare matched sections processed under the same conditions before changing the antibody concentration (standard IHC practice). Include a control section with expected PRCP staining in every run; kidney tubular cells are reported as high staining in tissue IHC (HPA tissue IHC). If only older or heavily processed blocks stain weakly, test retrieval and primary-antibody incubation on adjacent sections, but treat the processing explanation as a hypothesis (standard IHC practice).

Where should convincing PRCP signal appear in a paraffin section?

Look for cytoplasmic, granular staining rather than a uniformly nuclear pattern: PRCP is annotated to lysosomes, and tissue IHC reports a granular cytoplasmic pattern (UniProt P42785 localisation; HPA tissue IHC). Vesicular localisation in cell imaging provides a second compartment-level expectation, though its appearance need not match chromogenic tissue sections exactly (HPA subcellular). Evaluate the pattern within identifiable cells before judging overall stain intensity; kidney tubular cells and adrenal glandular cells are reported as high staining examples (HPA tissue IHC). A smooth, diffuse deposit spanning cell borders calls for checks of background, tissue preservation and detection chemistry (standard IHC practice).

Could epitope choice change what the PRCP antibody detects?

PRCP has 2 annotated isoforms and is processed from a precursor into a chain spanning residues 46–496 (UniProt P42785 isoforms and processing). Its signal peptide and propeptide occupy residues 1–21 and 22–45, respectively, so an antibody's mapped epitope matters when interpreting mature-protein staining (UniProt P42785 processing). Six glycosylation sites are annotated, which is another reason to check the antibody's stated immunogen or epitope before assuming all molecular forms are equally detectable (UniProt P42785 glycosylation; standard antibody validation practice). If epitope information is unavailable, describe the result as antibody staining and compare it with an independently validated reagent or control (standard IHC practice).

How can IF help assess an ambiguous chromogenic PRCP pattern?

Use IF/ICC as a separate corroborating experiment: vesicular PRCP localisation has been reported in U2OS images, while paraffin-section IHC shows granular cytoplasmic staining (HPA subcellular; HPA tissue IHC). For a tissue comparison, multiplex PRCP with a marker identifying the expected cell population, such as kidney tubular cells, and assess whether signals occur in the same cells (HPA tissue IHC; standard IF practice). Choose a far-red fluorophore and include an unstained section to assess tissue autofluorescence (standard IF practice). Because PRCP is intracellular and has no annotated transmembrane segment, optimise permeabilisation against the antibody's mapped epitope; do not assume its accessibility from topology alone (UniProt P42785 localisation and topology; standard IF practice).

What should I check when PRCP staining looks diffuse or widespread?

First compare the primary-antibody slide with a no-primary control and inspect where chromogen accumulates, including tissue edges, folds and damaged areas (standard IHC practice). Block endogenous peroxidase before horseradish-peroxidase detection, and use appropriate protein blocking and washes to limit nonspecific signal (standard chromogenic IHC practice). The selected tissue image used catalog antibody at 1:200 with an overnight 4°C incubation, providing a documented starting condition rather than a guaranteed optimum for every specimen (caption A04829-1). Interpret a diffuse wash of color cautiously because reported PRCP tissue staining is granular and cytoplasmic (HPA tissue IHC).

How should I score PRCP staining across tissue sections? ⚠ ANSWER MARKED FOR VERIFICATION

Define the cell population and compartment before scoring; PRCP tissue staining is reported as granular and cytoplasmic, with high staining in kidney tubular cells (HPA tissue IHC). For chromogenic IHC, report the percentage of positive target cells and an intensity-based H-score, or quantify positive-cell density per mm² in a defined region (standard IHC quantification practice). Normalise cell counts to the number of evaluable cells and area measurements to viable tissue area, excluding folds and necrosis by a prespecified rule (standard IHC quantification practice). Apply identical thresholds and imaging settings across specimens, and retain control-slide results alongside the scores (standard IHC practice).

How do I distinguish credible PRCP staining from artefact?

Credible staining should occur within identifiable cells and show the granular cytoplasmic pattern reported for PRCP tissue IHC, consistent with its lysosomal annotation (HPA tissue IHC; UniProt P42785 localisation). Compare candidate positives with kidney tubular cells, a reported high-staining population, and review unexpected staining against a no-primary control (HPA tissue IHC; standard IHC practice). Nuclear-only signal, edge staining, necrotic deposits or color generated by endogenous peroxidase warrants investigation before calling cells positive (standard chromogenic IHC practice). Tissue expression alone cannot validate the antibody: the HPA tissue profile is approved but notes low consistency between staining and RNA data and pending external verification (HPA tissue IHC).

Boster reagents

Best PRCP / Lysosomal Pro-X carboxypeptidase IHC Antibodies

A04829-1 is listed for human and mouse IHC and IF (catalog: applications, reactivity); its real IHC image shows paraffin-embedded human lung squamous cell carcinoma (IHC image caption).

Real IHC data Immunohistochemical analysis of paraffin-embedded human Squamous cell carcinoma of lung. 1, Antibody was diluted at 1:200 (4° overnight). 2, Tris-EDTA, pH9.0 was used for antigen retrieval. 3, Secondary antibody was diluted at 1:200 (room temperature, 45min).

Anti-PRCP Antibody

Cat # A04829-1

View product →

A04829-1 has an IHC image from paraffin-embedded human lung squamous cell carcinoma (IHC image caption). It is listed for human and mouse IHC and IF, but no IF image is supplied (catalog: applications, reactivity, IF image alts).

Which to pick: For tissue IHC, choose A04829-1: its image caption documents paraffin sections, Tris-EDTA retrieval at pH 9.0, and primary antibody at 1:200 overnight at 4°C; the fixative is unreported (IHC image caption). For IF, A04829-1 is listed, but ICC validation and an IF image are unreported (catalog: applications, IF image alts). For cross-species work, A04829-1 lists human and mouse reactivity, though the shown IHC tissue is human; the antibody is rabbit-hosted and its clonality is unreported (catalog: reactivity, host, clone; IHC image caption).

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

References

UniProt Consortium. UniProt entry P42785 (PCP_HUMAN, Lysosomal Pro-X carboxypeptidase).
Human Protein Atlas. PRCP tissue IHC expression (reliability: Approved).
Human Protein Atlas. PRCP subcellular location (ICC-IF): Localized to vesicles..
Human Protein Atlas. PRCP antibody validation summary (2 antibodies).
Pro-opiomelanocortin and its Processing Enzymes Associate with Plaque Stability in Human Atherosclerosis - Tampere Vascular Study. Scientific reports 2018 — PMC6180013.
Identification of novel molecular signatures of IgA nephropathy through an integrative -omics analysis. Scientific reports 2017 — PMC5567309.
Prolyl carboxypeptidase in Agouti-related Peptide neurons modulates food intake and body weight. Molecular metabolism 2018 — PMC5985234.
Prolylcarboxypeptidase promotes IGF1R/HER3 signaling and is a potential target to improve endocrine therapy response in estrogen receptor positive breast cancer. Cancer biology & therapy 2022 — PMC9639567.
PubMed PMID:8344943 — UniProt-cited evidence.
PubMed PMID:14702039 — UniProt-cited evidence.
PubMed PMID:19054851 — UniProt-cited evidence.