PAS-D Stain Service: Remove Glycogen, Reveal Pathology with Clarity

At iHisto, we offer PAS-D staining to precisely visualize basement membranes, fungal organisms, and mucin by removing glycogen interference. This specialized refinement of PAS staining is ideal for renal biopsies, liver pathology, and fungal infection analysis in both preclinical and clinical research.

🧪 Overview 

PAS-D (Periodic Acid–Schiff with Diastase) improves histological interpretation by enzymatically removing glycogen, allowing clearer detection of:

• Basement membranes

• Mucin and glycoproteins

• Fungal walls

• Other non-glycogen polysaccharides

It’s especially useful where overlapping carbohydrate signals may obscure pathology in standard PAS stains.

🧬 How PAS-D Staining Works

The PAS-D method consists of two stages:

1. Diastase Digestion – α-amylase removes glycogen, a normal storage product

2. PAS Reaction – Periodic acid oxidizes other carbohydrates, which react with Schiff reagent to form bright magenta deposits

Color Results:

• Glycogen → removed

• Basement membranes, mucins, fungal walls → magenta

• Nuclei → blue or purple (hematoxylin counterstain)

• Background → pale or unstained

🔬 Step-by-Step Staining Process

1. Fixation & Sectioning – FFPE tissue is cut at 4–6 µm

2. Deparaffinization & Hydration – Slides are processed to water

3. Enzymatic Digestion – Diastase applied to remove glycogen

4. Periodic Acid Oxidation – Aldehyde groups formed from other carbohydrates

5. Schiff Reagent Application – Forms magenta stain at positive sites

6. Counterstaining & Mounting – Hematoxylin applied; slides dehydrated and coverslipped

🎯 Applications of PAS-D Staining 

This stain is crucial when glycogen obscures key pathology, especially in:

• Renal biopsies – Basement membrane, brush border, and mesangial matrix without glycogen interference

• Liver histology – Glycogen storage diseases, early fibrosis, structural integrity

• Fungal detection – Candida, Aspergillus, Histoplasma differentiation

• Tumor analysis – Clarify mucin and glycoproteins in adenocarcinomas

• Glycogen metabolism research – Compare with standard PAS to evaluate enzymatic effect

✅ Why Choose iHisto for PAS-D 

• ✅ Complete glycogen removal for accurate visualization

• ✅ Validated staining for human and animal tissue

• ✅ High contrast of non-glycogen carbohydrates

• ✅ Digital slide scanning and secure delivery

• ✅ Pathologist interpretation and quantification available

We support nephrologists, hepatologists, pathologists, and infectious disease teams with clear, artifact-free PAS-D staining.

❓ FAQs 

• What does PAS-D stain detect?
  Carbohydrates such as basement membranes, mucins, and fungal cell walls — excluding glycogen.

• How is PAS-D different from PAS?
  PAS-D uses diastase enzyme to remove glycogen before Schiff staining, improving clarity in glycoprotein-rich areas.

• Is this useful for kidney biopsies?
  Absolutely. PAS-D is a core stain in renal pathology, especially for evaluating GBM thickness and tubular changes.

• Can you digitize the slides?
  Yes — all PAS-D-stained slides can be scanned at high resolution and delivered securely via HistoCloud or encrypted storage.

📩 Request a Quote or Consultation 

Looking for precise, artifact-free detection of complex carbohydrates? iHisto’s PAS-D staining service enhances clarity and diagnostic confidence — whether you’re researching kidney pathology, fungal infections, or metabolic conditions.

👉 Request a Quote or email us at info@ihisto.io