obain

Couldn't you lay a total immersion thermometer in the groove between the slots? Some of the older heat blocks were designed that way.

Recently purchased a Labnet Accublock Dry Bath from Market Lab Inc. You can get different blocks for 10 or 12 mm tubes. It has digital setting and digital readout. We validated with an external thermometer in multiple wells over multiple days. Maintains temp within +/- 0.1 deg C. It's nice having the digital display so you can tell that it has not been unplugged or turned off. Owen Bain