Method and apparatus for accessing a site on a biological substrate

A system for accessing selected areas of biological substrates, comprising:

• a biological substrate;
• a substrate tray operable to receive said biological substrate;
• a platform operable to receive said substrate tray;
• an access device;
• a global fiducial level system located on at least one of said platform and said substrate tray, wherein said global fiducial level system is associated with a first area;
• a local fiducial level system located on said biological substrate and associated with a second area;
• a sensor, wherein said sensor senses said global fiducial level system to determine a position of said access device relative to said first area, and wherein said sensor senses said local fiducial level system to determine a position of said access device relative to said second area;
• a substrate identifier;
• and
• a data storage device comprising at least a first data file associated with said substrate identifier, wherein information related to a position of a third area with respect to said local fiducial level system is stored in said at least a first data file.