Slide Guide Used in Fluorescence Microscope
- Thursday, 01 February 2007
In the USA and other developed countries, cancer is responsible for 25% of all deaths. In spite of the most recent advances in cancer research, by far the best curative treatment for the disease is early detection. Such technology revolves around quick identification of malignant cells, necessitating clean, crisp images for oncologists. The CellTracks Analyzer II by Immunicon (Huntington Valley, PA) is a semi-automated fluorescence microscope system used to count and characterize fluorescently labeled cells that are immuno-magnetically selected and aligned. The SEBS-B type miniature slide guide, from NB Corp. of America (Wood Dale, IL), is tapped as part of the microscope’s system of axes.
Cancer is a growth of cells that is unrestricted and inchoate. As a term, “cancer” usually refers to malignant neoplasm only, those cancers characterized by spreading to other sites in a process called metastasis. In a metastatic invasion, cancer cells break off of the primary tumor and travel to remote locations in the body via the blood stream, lymphatic system, or both and there take root in the form of a new tumor. While metastasis is a characteristic of late-stage tumor growth, doctors and patients usually do not take the chance at any stage of the disease. Detection methodologies, from mammography to the CellTracks Analyzer, must be able to clearly differentiate cancerous cells from a background of otherwise healthy cells that number in the billions. The CellTracks Analyzer II tests the blood of the patient, searching for circulating tumor cells (CTC) that have since broken away from the primary tumor and flowing through patient’s bloodstream.
A fluorescence microscope is a light microscope used to study properties of substances using fluorescence and/or phosphorescence rather than, or in addition to, the reflection and absorption techniques of conventional microscopes. The light used is also usually more intense than convention counterparts.
The CellTracks Analyzer II, designed to count and characterize CTCs, contains several NB components; the stainless SEBS-B guides are found in three (of the four) axes, consisting of a block and guide rail, both of which have two precision ground raceway grooves. Wanting to keep the design compact, Immunicon had to pay close attention to the size of all the components used. The two-raceway and four-point contact structure of the SEB-B minimizes their height, making them suited for the limited space provided; the SEBS is the smallest and lightest slide guide series in NB’s stock. Due to the need for fine precision for the viewer, the ability of the guides to maintain a constant level of friction and running (Immunicon used the nonretained-ball version of the SEBS-B) was a determining factor in the CellTracks’ design. Immunicon choose the SEBS-B specifically for its preload; for the fact that it has no “play.” Two axes using the slide guide control the movement of the sample, requiring an unvarying smoothness of motion. The third SEB-S axis moves one of three optical blocks, called filter cubes, into position in the optical path of the microscope. This cube provides a convenient means to change the microscope’s mirror without direct handling of either the mirror or filters.