During tissue sectioning, tissues containing bone or calcified lesions cannot be directly embedded in paraffin for sectioning. Due to the density difference between calcium and paraffin, intact sections are difficult to obtain. For calcium‑containing tissues, decalcification should be performed after fixation, or fixation and decalcification can be carried out simultaneously, followed by downstream procedures including dehydration, clearing, wax infiltration, embedding and sectioning. A wide range of decalcifying agents are available, such as organic acids, inorganic acids, ethylenediaminetetraacetic acid (EDTA), and electrolytic decalcification.
Plank‑Rychlo Decalcifying Solution is mainly composed of dilute acid, ammonium chloride or aluminium chloride, formic acid and other components. Its advantages are as follows:
① Fast‑acting, with shorter processing time than JYBL‑Ⅰ (Aladdin Cat.No.: J1525466), generally complete within 24 h;
② Low damage to tissue structure;
③ Thorough decalcification.
This decalcifying solution is especially suitable for routine decalcification of bone specimens in pathology laboratories. However, chemical methods are not recommended for determining the decalcification endpoint, and it may cause certain damage to tissue architecture.
This reagent is for research use only and is not intended for clinical diagnosis or other applications.
Materials to be prepared
1. Distilled water or PBS
2. Heating device or microwave oven, dedicated glass container for decalcification
Operating Procedures (For Reference Only)
1. For bone‑tissue decalcification, samples should not be excessively thick; the recommended thickness is approximately 3‑5 mm.
2. After tissue fixation, rinse samples 3 times with distilled water or PBS, 20 min each time.
3. Transfer tissues into Plank‑Rychlo Decalcifying Solution at 20‑30‑fold volume and decalcify for 24 h. To accelerate decalcification, incubate at 37 ℃.
4. Rinse several times with distilled water.
5. Proceed with standard dehydration and embedding.
Precautions
1. Bone tissues shall be fully fixed prior to decalcification, and tissue blocks should be kept as small as possible.
2. Bone tissues should be decalcified after fixation, or fixation and decalcification shall be performed concurrently. Decalcification prior to fixation is not allowed to minimize tissue damage.
3. For 5 mm‑thick bone blocks, decalcification usually takes 24‑36 h.
4. Moderate heating accelerates decalcification; temperature should generally not exceed 37‑40 ℃. Excessively high temperature may cause bone tissue disintegration, and the temperature must never exceed 60 ℃.
5. Check the decalcification progress periodically. Complete decalcification is required to avoid under‑decalcification or over‑decalcification. Over‑decalcification aggravates tissue damage and compromises staining results. Decalcification should be sufficient for sectioning while keeping the processing time as short as possible.
6. Avoid metal containers for decalcification procedures.
7. Thoroughly rinse specimens with tap water upon completion of decalcification to prevent interference with staining.
8. Wear a lab coat and disposable gloves for your safety and health during operation.
Appendix
Determination of Decalcification Endpoint (Physical Method):
Use needle piercing, pinching or forceps clamping. Terminate decalcification when bone tissue softens or no resistance is felt during needle piercing. Physical detection may cause certain damage to tissue structure; avoid excessive force and repeated testing.
