Godwin O. Avwioro
The staining quality of microwave processed tissues was compared with the staining quality of the conventional paraffin wax processed tissues. Normal lung, kidney, liver, intestine and heart tissues obtained from an adult Wistar albino rat were fixed in 10% formol saline and processed by the conventional paraffin wax method. The twin specimens were also processed by the microwave method. Sections were cut with the rotary microtome, paired and stained by heamatoxylin and eosin method for general tissue structure, Weigert's van Gieson iron haematoxylin for collagen fibres, Verhoeff's van Gieson iron haematoxylin for elastic fibres, periodic acid Schiff reaction for neutral mucopolysaccharides, Gordon and Sweet's method for reticular fibres, Alcian blue (pH2.5) for carboxylated and sulphated mucopolysaccharides, Congo red method for amyloid, Masson's trichrome for collagen and muscle fibres and Gomori's aldehyde fuchsin method for elastic fibres. Microscopically, there were no significant differences in the staining reactions of all the techniques when they were compared with the microwave processed tissues. Nuclear, cytoplasmic, extracellular and intracellular materials appeared the same with the conventionally processed tissues by the paraffin wax method. Muscles, collagen fibres, elastic fibres and reticular fibres were also stained the same way as the conventionally processed tissues. Neutral carbohydrates and amyloid were equally of the same appearance with the conventional paraffin wax method. However, there was significant tissue shrinkage in the conventional method which was not apparent microscopically. Microwave method is faster, cheaper and prevents the use of xylene which is harmful to humans
