Paraffin Embedding; a Graded-Temperature Table Used with Multiple Blocking for Enhanced Efficiency

Details are given for the construction of a graded-temperature table having a cool and hot side. Aluminum baking pans smeared with glycerol are used to cast the multiple paraffin blocks. These are loaded with paraffin wax from an electrically heated paraffin wax dispenser incorporated in the graded-temperature table and the pieces of tissue and labels orientated in them. The pans are then moved to the cool side of the table before finally floating them on cold water to harden the wax. Arranged above the heated side of the table are two infrared lamps which prevent premature solidification of the surface of the wax. After removing the solid, multiple-block slabs from the pans, the infrared lamps are used to soften the wax to a cheese-like consistency. Individual blocks are cut apart and trimmed around their sides with single strokes to produce smooth-sided blocks which are ready for attaching to wooden holders, adapted to the microtome chuck.