A rapid and simple staining method, using toluidine blue, for analysing mitotic figures in tissue sections

Area of Science:

• Histopathology
• Cell Biology
• Cancer Research

Background:

• The mitotic index is crucial for cancer pathology, assessing tumor cell proliferation.
• Accurate and efficient methods for detecting mitotic figures are essential for clinical diagnosis.

Purpose of the Study:

• To develop a rapid and efficient staining method using Toluidine Blue (TB) for detecting mitotic figures.
• To optimize the staining procedure for formalin-fixed paraffin-embedded human and rat tissues.
• To enable accurate quantification of the mitotic index in tumor samples.

Main Methods:

• Sections were stained with 0.01% Toluidine Blue at acidic pH (3.5 for human, 4.5 for rat) after RNA removal.
• Mitotic figures were visualized with enhanced intensity compared to other cellular structures.
• Quantitative assessment of total nuclei was performed on adjacent sections using Feulgen reaction and TB staining for image cytometry.

Main Results:

• The optimized Toluidine Blue staining method effectively highlighted mitotic figures in both human and rat tissues.
• The procedure demonstrated superior staining intensity for mitotic figures over other cellular components.
• Accurate mitotic index determination was achieved by correlating mitotic figure counts with total nuclei counts on serial sections.

Conclusions:

• Toluidine Blue offers an efficient and rapid staining technique for identifying mitotic figures in histopathological samples.
• This method facilitates accurate quantification of the mitotic index, aiding in cancer diagnosis and prognosis.
• The developed procedure is valuable for both research and clinical applications in cancer pathology.