I have used plastic coplin jars with small holes punctured in the
plastic lids. The slides are placed in the buffer filled coplin jars,
lids screwed on, and then microwaved on high until bubbles appear
from the holes. The power setting is then turned down to defrost
setting and microwaving continued for 15 to 20 min. Every five
minutes, the power is pushed up until bubbles again appear. After
cooling, the slides are ready for immunostaining.

This method is good for small numbers of slides (up to 5), but for
larger numbers, a pressure cooker is better.

Tony Henwood
www2.one.net.au/~henwood