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Biomedical subjects

R S Demaree

Publications and source records attributed to R S Demaree.

13 recordsLinked to original sources

Four-hour processing of clinical/diagnostic specimens for electron microscopy using microwave technique.

A protocol for routine 4-hour microwave tissue processing of clinical or other samples for electron microscopy was developed. Specimens are processed by using a temperature-restrictive probe that can be set to automatically cycle the magnetron to maintain any designated temperature restriction (temperature maximum). In addition, specimen processing during fixation is performed in 1.7-ml microcentrifuge tubes followed by subsequent processing in flow-through baskets. Quality control is made possible during each step through the addition of an RS232 port to the microwave, allowing direct connection of the microwave oven to any personal computer. The software provided with the temperature probe enables the user to monitor time and temperature on a real-time basis. Tissue specimens, goat placenta, mouse liver, mouse kidney, and deer esophagus were processed by conventional and microwave techniques in this study. In all instances, the results for the microwave-processed samples were equal to or better than those achieved by routine processing techniques.

Adenoviridae Infections

Microwave fixation: understanding the variables to achieve rapid reproducible results.

The use of microwave irradiation for rapid chemical fixation of tissues in electron microscopy is a subject of current interest. The effects of water load size and location, sample placement in the oven cavity (hot or cold spots), and time on tissue preservation were examined. The use of a microwave container (4 dram vial) encased in 60 ml of ice in a 100 ml polyethylene beaker and a 0% power setting between two 100% power settings (time interval) provided reliable control of temperature during microwave irradiation. High brightness neon lights provided a quick and easy method to identify and map hot and cold spots within the oven cavity. Using microwave irradiation for rapid glutaraldehyde and osmium tetroxide fixation of tissues (Pacific yew needle and mouse kidney and liver) for electron microscopy yielded preservation equal or better than routine immersion fixation when a time interval, a cold spot (as the sample location), and an ice-encased vial were used during microwave fixation. These adaptations provided reliable control of fixation conditions in an 800 watt laboratory microwave oven.

Animals

Immunoperoxidase localization by electron microscopy of soluble egg antigen and human IgG in circumoval precipitin reactions around Schistosoma mansoni eggs.

Soluble egg antigen and human IgG were localized by the unlabelled antibody enzyme technique for electron microscopy on Schistosoma mansoni eggs having circumoval precipitin reactions. Reaction products indicating the presence of soluble egg antigen were on portions of the circumoval precipitate outside the egg, between the eggshell and vitelline membrane, and between the vitelline membrane and miracidium inside the egg. Reaction products indicating human IgG were only found on portions of the circumoval precipitate external to the eggshell.

Animals