Evaluation of the Conventional Versus Two Rapid Microwave Processing Techniques Using the Masson Trichrome Histochemical Methtod

Aims: To evaluate the quality of paraffin blocks produced using the microwave and without the use of xylene. To evaluate the compatibility of the rapid microwave processing techniques on the histochemistry of collagen and muscle fibre as well as nuclear, cytoplasmic and extracellular components.

Study Design: Harvesting and fixation of tissues in 10% formalin. Grossing into triplicates, processing using three different techniques, checking for retraction of blocks, checking the quality of paraffin ribbon, Staining using the Masson Trichrome technique, grading of section quality and staining characteristics.

Place and Duration of Study: Anatomy Department, Nnamdi Azikiwe University, Nnewi Campus and National veterinary Research institute, Vom, Nigeria. The work was done between August and December, 2014.

Methodology: Liver, kidney and oesophagus were harvested from an apparently healthy rabbit. Human cervix, prostate, testis and prostate were obtained. All samples were fixed in 10% buffered formalin, cut into triplicates and processed using the three techniques, sectioned and stained simultaneously using the Masson Trichrome technique and evaluated.

Results: Processing cycles and reagent consumption per cycle were greatly reduced in the microwave techniques. Paraffin blocks as well as ribbons produced from the three techniques were of comparable quality. Though tissue integrity was comparable among the three techniques, the stroma of the cervix was better retained in the microwave with vacuum method. Dye uptake as well as section thickness were comparable among the three techniques. Nuclear, cytoplasmic and extracellular components presented with comparable histochemistry.

Conclusion: The rapid microwave techniques are cheap and fast with good ribonning. Reagent toxicity is greatly reduced as xylene is excluded. Muscle fibre and collagen fibre histochemistry for the rapid microwave methods are comparable to that of the conventional method. Cervical stroma is better retained in the rapid microwave methods than in the conventional method of paraffin wax processing. Microwave techniques should be encouraged since they can help to produce quality paraffin section within the shortest time possible at a cheaper rate than the conventional method without compromising section quality and tissue histochemistry.