Leica SP2600 Ultramiller

The ideal system for specimen surface preparation is the Leica SM2500 sledge microtome with the ultramilling attachment Leica SP2600.

Ultramilling is often a viable alternative to standard microtomy and saw microtomy in sample preparation. Especially with difficult specimens, where hard and soft materials are located side by side in one specimen block, the results achieved are truly excellent.

Impressive results of unmatched quality have also been achieved in bone and teeth specimen preparation.

Please note: The instrument cannot be used to mill alloys or implants containing iron or ceramics.

Key Features

• Spindle rotation speed continuously adjustable between 500 and 3000 rpm, in 100-rpm steps
• Pre-adjustment device to accurately adjust the pre- and finishing-miller into the holders
• Variety of different diamond finishing millers for different applications
• Spindle rotation speed continuously adjustable between 500 and 3000 rpm, in 100-rpm steps
• Pre-adjustment device to accurately adjust the pre- and finishing-miller into the holders
• Variety of different diamond finishing millers for different applications

Detailed Description

Instead of preparing thin sections for transmitted light microscopy, a polished surface is prepared for examination under reflected light.

Principle:
Layer after layer of material, each layer of precisely the same thickness, is removed from a specimen block mounted onto a sledge travelling underneath a milling head consisting of a vertical, rotating spindle equipped with a diamond cutting tool on one and a balance weight on the other side.

The surface preparation procedure consists of two different steps: a preparation step carried out with a pre-miller and a finishing step during which a mirror-like surface with excellent edge definition is obtained.

Using the ultramilling technique makes it possible to track the area of interest in depth as the surface layer can be removed in micrometer steps.

Description of the pre-milling process:
The rotational speed of the spindle is adjustable from 500 to 3,000 rpm, the ideal speed in each case depending on the material being milled. Depending on the hardness of the material, material removal thickness can be adjusted starting from 1 µm per layer. To ensure high-quality final results the travelling speed of the sledge can also be adjusted according to the properties of each individual specimen being milled.

A diamond cutting tool with a triangular cutting geometry is used for the pre-milling step, where the block is trimmed down to the area of interest. Under the microscope, a pre-milled block surface will show a regular saw-tooth like pattern due to the triangular geometry of the pre-miller.

Description of the finishing step:
To obtain a smooth finished surface, the pre-miller is replaced by a finishing miller which removes the saw-tooth like pattern produced by the pre-miller leaving a perfectly even, mirror-like surface ready for investigation.

In addition to surface preparations for incident light investigation it is also possible to do thin preparations for transmitted light microscopy. For that purpose, a plane parallel specimen slice is prepared (e.g. using the Leica SP1600 saw microtome) and placed onto a vacuum table which keeps the slice in position during milling. The finished milled side of the specimen is glued onto a plexi-glass slide and finally the second specimen side is milled until the required thickness is achieved. Both sides of the slice are then milled until the desired thickness is reached.