A comparative study of microwave assisted and conventional tissue processing for preparing rat (Rattus norvegicus) tissues for microscopy

Abstract

The discovery of microwaves is believed to have brought a revolutionary improvement in many scientific fields with microscopy and histopathology being among them. Microwave assisted tissue processing of pathologic material is becoming increasingly desirable to fulfil the needs of clinicians treating acutely ill animals and patients. This technique shortens the time for tissue processing from days to hours and execute the needs of the patients and animals in need of diagnosis as well as those of the physician by improving the use of reagents while reducing or eliminating their toxicity and places the laboratory in a better position to meet the demands of the pathologists. Few data exist comparing quality of microwave-processed tissues with that processed by conventional means on rat (Rattus norvegicus) for microscopic analysis. This study was conducted to determine the efficacy of the microwave tissue processing method for rat specimens by comparing microwave assisted tissue processing with the conventional method, based on the clarity of nuclei, cytoplasm, staining intensity and cellular detail of tissues processed by each method. A total of eight specimens were cut into two equal parts and each part was processed by the two processing techniques. Haematoxylin and eosin staining was performed at the same time and grading was done by two pathologists. An independent samples t-test using SPSS 21 was used to test for significant differences. The parameters (staining intensity, nuclear, cytoplasmic and cellular details) were scored higher in conventionally processed sections as opposed to the domestic microwave method. The P-values for the mean scores showed a significant difference for all the parameters on sections processed by CTP (conventional tissue processing) and DMTP (domestic microwave tissue processing), nuclear detail , t (14) = 2.170, (p= 0.048, p < 0.05), cytoplasmic detail t (14) = 4.194, (p= 0.001, p < 0.05) ,staining intensity t (14) = 2.297 (p= 0.038, p < 0.05), and cellular detail t (14) = 2.668 (p= 0.018, p < 0.05). Domestic microwaves can thus be used for tissue processing which shortens the time for tissue processing but however cannot produce quality slides comparable to those made from conventional processing.