Leica TCS SPE and SPE2

The Leica TCS SPE and SPE2 confocal microscopes are almost identical. They are basic "personal" confocals designed principally for scanning samples that have been fixed and mounted on slides. They can be used to image living samples, but have a couple of drawbacks in this respect: they have no 'cage type' incubation system, so living mammalian cells and tissues must be imaged using either a Warner Instruments perfusion system or Oko-Labs equipment for imaging specimens on upright microscopes using dipping lenses. A motorised dichroic mirror block has to switch positions between 405/532 and 488/635 illumination paths, which will limit the speed with which green and red fluorophores (or blue and far red fluorophores) can be imaged in live microscopy procedures. All SPE confocals have only one photomultiplier tube (PMT) detector, so simultaneous acquisition of multiple channels is not possible. All multi-channel acquisition is done sequentially. A galvanometer driven stage insert is used to change the focus when optically sectioning samples. The speed of this device means that XZY scans are possible in addition to the conventional XYZ scan and single colour 3D time series acquisitions can be quite fast. The ACS objective lenses, which have been designed to correct for colour registration errors caused by chromatic aberration, do not have a flat field, so best results are achieved at zooms ≥1.6.