Microwave Fixation: In Situ Tick (Acari: Ixodidae) Histoanatomy, Thin Sectioning of Tick Tissues, and Antigen Preservation in Mouse Spleen

Abstract

Microwave irradiation was used for the fixation of eggs, nymphs, and adult Boophilus spp. ticks. Although optimal temperatures for fixation of the different tick stages varied, heating to 58 degrees C of adult ticks submerged in either PBS or fixative was found to be sufficient. After microwave fixation, whole adult ticks, hand held, were sectioned with a sharp razor blade. The resulting sections revealed the in situ histoanatomy of the tick. Thin sections of ticks were obtained after either paraffin or polyester wax embedding. Microwave fixation combined with polyester wax embedding made serial thin sections of the different stages of Boophilus ticks possible. The technique preserved antigens as demonstrated by the immunostaining of lymphocytes and erythrocytes infected with Babesia microti in mouse tissues subjected to the same treatment as the ticks. With the microwave fixation-polyester wax technique, the specimen preparation time from fixation to the section on the glass slide was reduced to less than 8 h.

Artifacts from Rapid Microwave Processing of Trematode Tissues (Ascocotyle pachycystisandleighi)

“…Carranza et al (1990) reported excellent preservation for tick tissues heated in a microwave, by using phosphate buffered saline (PBS) alone, rather than fixative.…”

“…Positive results have been reported by many workers who have used MW processing for light microscopy. Carranza et al (1990) reported excellent preservation for tick tissues heated in a microwave, by using phosphate buffered saline (PBS) alone, rather than fixative. However, since a dissecting microscope, (thus low magnification) was used, only gross anatomical structures were examined.…”