Scope 8 micron systematic shift in z position on thermal expansion during laser scanning. The second position acquisition on all the following overnight sessions and on are incomplete: 02-08-11: MP09_22C_y_hb, MP10_22C_sna_y,
01-31-11: MP10_sna_y_22C, MP10_sna_y_22C_b.
Threshold of .01 leads to classification of aberrations:
Aberrant transcript detection in top layer does not correspond to expressing region. Compare total dots image (left) to the subset of dots localized correctly in interior tissue (right). 
Front right piston of stage lever position slipped, leaving piston completely depressurized. Fixed by Jacques. Need to monitor level and air suspension for future slippage.