Techniques for combining light microscopy and scanning electron microscopy: a survey of the literature

Natural color scanning electron microscopy based on the frequency characteristics of the human visual system

The principles of image formation in natural color scanning electron microscopy (NC-SEM) are discussed in detail. This method is based on the frequency characteristic of the human visual system. It is shown that the Mach effect and masking effect are important in the characteristics. The former, which can enhance structural details, is visually similar to the edge effect in secondary electron (SE) images, and the latter is required for proper representation of very degraded color information obtained from a light microscope. When using these effects suitably, an NC-SEM image with the resolution equivalent to that of an SEM image can be acquired, though it is composed of an SEM image and a special video microscopy (VM) image with a resolution much lower than the SEM image of the identical view. The NC-SEM is more effective than the SEM in observation. interpretation, and analysis of various samples with important color information.

Correlative light and backscattered electron microscopy of bone--Part I: Specimen preparation methods

A method for preparing nondecalcified bone and tooth specimens for imaging by both light microscopy (LM) and backscattered electron microscopy in the scanning electron microscope (BSE-SEM) is presented. Bone blocks are embedded in a polymethylmethacrylate (PMMA) mixture and mounted on glass slides using components of a light-cured dental adhesive system. This method of slide preparation allows correlative studies to be carried out between different microscopy modes, using the same histologic section. It also represents a large time savings relative to other mounting methods whose media require long cure times.

Combined conventional transmission, scanning, and high-voltage electron microscopy of the same blood vessel for the study of targeted inflammatory cells in blood-brain barrier inflammation

The microvasculature of brains and spinal cords from mice subjected to chronic relapsing experimental autoimmune encephalomyelitis (CREAE) was studied using three different electron microscopic techniques. Blood vessels were initially examined by scanning electron microscopy. This allowed for the investigation of topographical changes of the luminal aspects of endothelial cells (ECs) and identification of targeted inflammatory cells (ICs) attached to the ECs. The same blood vessel areas with attached ICs examined by scanning electron microscopy were subsequently trimmed, processed for routine conventional transmission electron microscopy, and plastic embedded. Thin (80 nm) sections were cut and evaluated. Semithick (0.5-0.75 microns) serial sections of this material were examined by high-voltage electron microscopy. Data presented here described a useful technique for combining several ultrastructural techniques that permits simultaneous topographic and cross-sectional examination of selected regions of individual blood vessels or specifically targeted ICs.

A morphologic study of osteoclasts isolated from osteopetrotic microphthalmic (mi/mi) mouse and human fetal long bones using an instrument permitting combination of light and scanning electron microscopy

Cell surface structures of isolated osteopetrotic (mi/mi) and normal murine (+/+ and +/mi) and human osteoclasts were examined in a microscope combining light and scanning electron microscopy (LM/SEM). Tartrate-resistant acid phosphatase (TrAP) was used as an histochemical osteoclast marker. In osteopetrotic bone, as in normal murine bone, TrAP activity was exclusively seen in osteoclasts and preosteoclasts and was therefore judged a suitable marker for identification of isolated osteoclasts. A method was developed for preparation of LM/SEM specimens from osteoclast-enriched cell suspensions. In the LM/SEM isolated osteoclasts were easily recognized in the LM mode by TrAP contents. In specimens prepared from murine cells, but not human cells, LM identification of osteoclasts by TrAP was essential. This was in particular true for small, mononuclear, mi/mi osteoclasts. All osteoclasts examined had a villous appearance and were well spread over the glass substrate. There were no differences in cell surface morphology and in adherence to glass between osteopetrotic and normal osteoclasts.