TRAP Stain Service: Osteoclast Detection for Bone Biology and Skeletal Research

At iHisto, we provide precise TRAP staining to visualize osteoclasts, the bone-resorbing cells essential for understanding skeletal remodeling and bone disease. Our protocol delivers bright red TRAP-positive cells on decalcified bone sections — optimized for both research and preclinical development.

🧪 Overview

TRAP (Tartrate-Resistant Acid Phosphatase) staining identifies osteoclasts based on their enzymatic activity, resistant to inhibition by tartrate. This enzymatic histochemical technique is widely used in:

• Osteoporosis models

• Bone remodeling and resorption studies

• Fracture healing and arthritis research

• Cancer bone metastasis

• Bone-implant integration and biomaterials testing

iHisto’s optimized TRAP staining highlights bone-resorbing cells clearly and consistently, supporting both qualitative and quantitative analysis.

⚙️ How TRAP Staining Works

TRAP is an enzyme expressed by osteoclasts, cleaving a colorless substrate into a bright red precipitate when tartrate-resistant phosphatase activity is present.

Color Results:

• Osteoclasts (TRAP-positive cells) → bright red

• Bone/background matrix → colorless or pale blue (if counterstained)

• Nuclei → blue or purple (hematoxylin or methyl green)

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This specificity allows accurate osteoclast counting and activity assessment in bone sections.

🧬 Step-by-Step Staining Process

1. Fixation & Decalcification – Bone is gently decalcified to preserve enzyme activity

2. Sectioning – FFPE tissues cut at 4–6 µm

3. TRAP Substrate Incubation – Naphthol AS-BI phosphate + tartrate buffer

4. Color Development – Fast Red yields red staining in TRAP+ cells

5. Optional Counterstain – Hematoxylin or methyl green enhances contrast

6. Mounting – Aqueous medium preserves enzymatic product integrity

🔬 Applications of TRAP Staining

TRAP staining is a cornerstone method in bone and skeletal histopathology.

Common use cases:

• Osteoporosis and bone loss evaluation

• Fracture repair and remodeling studies

• Osteoclastogenesis assays

• Bone metastasis or tumor–bone interface

• Drug toxicity on bone turnover

• Bone scaffold and implant testing

We support GLP and non-GLP projects for CROs, academic labs, and pharmaceutical teams.

✅ Why Choose iHisto for TRAP Staining

• ✅ Crisp, specific detection of TRAP-positive osteoclasts

• ✅ Validated for decalcified rodent, primate, and human bone tissue

• ✅ Compatible with femur, tibia, vertebrae, cranial bone, and more

• ✅ Digital slide scanning and manual or automated quantification

• ✅ Optional histomorphometry, pathology scoring, and integration with H&E panels

❓ FAQs 

• What does TRAP staining detect?
  It reveals tartrate-resistant acid phosphatase activity, a signature of osteoclasts and other specialized cells.

• Is TRAP used only for bone?
  Primarily yes, but it can occasionally mark TRAP+ cells in spleen, lymph nodes, and macrophage-rich tissues.

• What types of samples are accepted?
  Decalcified FFPE bone from mouse, rat, rabbit, or human tissue — including long bones, skull, and spine.

• Do you provide digital images and counts?
  Yes — we offer whole-slide imaging, plus optional osteoclast counting (manual or automated).

📩 Request a Quote or Consultation 

Studying osteoclast activity in bone loss or skeletal repair models? iHisto delivers high-resolution TRAP staining for confident analysis of bone remodeling, resorption, and therapeutic impact.

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