| HaSoTec Chemotaxis Analyzer HCA-200 |
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| Chemotaxis measurements using the Boyden technique |
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| There are several cell lines that can be animated to start moving by chemical factors. To characterize this movement, the Boyden technique uses a membrane with a well-defined diameter of its structures. For a constant period of time the cells have to move through this membrane, then the sample will be fixed. Now a statistic is generated where the number of cells is plotted against the distance the cells have moved. A given cell line will reproduce the same kind of exponential graphs. |
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| The measurement shown above was made with a sample of lymphocytes(Institute of Pharmacology, University of Rostock, Prof. Paegelow) in a Satorius Filter of 140µm thickness and a diameter of its pores of 8µm. Nikon immersion oil can be used to make this filter transparent. |
| This plot with its exponential decay is the average from 115 single measurement cycles from different locations of the sample. The X-axis shows the distance of cell movement. On the left side of the graph about 2500 cells are shown. This is the top layer of the filter and all cells from 115 frames. Each red point is another set of such 115 frames taken from another filter depth. The distance between red points here is 2µm and is software-selectable to 1µm, 2µm, 5µm or 10µm. At a depth of 6µm, still more than 1000 cells are found. This plot shows a 2-D measurement. Using a 2µm distance between frames this means that one cell can be shown 3...5 times. HCA-200 can measure the cells also in 3-D modes. In these statistics every cell is shown one time only. |
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| The manual counting of cells is a hard work. The HaSoTec Chemotaxis Analyzer counts the cells automatically. A focus motor moves the sample from frame to frame at a preselected distance. Another well-known method lets the cells move completly through the membrane over a longer time period and uses cell counters to get a ratio between cell counts of both sides of the membrane. These results are however inprecise. The Boyden technique provides for a much higher degree of precision. Lower cell quality will show double peaks and other visible effects. |
Counts using a 3-dimension analysis only make sense if the 3-D feature extraction is automatically made by a computer. HCA-200 has such software built-in which allows one to calculate the x,y,z coordinates of each cell.
The dialog box shown above allows one to visualize a measurement cycle after a 3-D feature extraction. The cube shown in dashed lines can be rotated in every direction using two scroll bars.
For two-dimensional analysis the results are shown already during the measurement. Each object is marked with red crosses in the central point of the cells. The size of each cross is in direct relationship to the size of the cell. |
| HCA-100 configuration (from 1993 to 1998) |
| Nikon Labophot, TV-camera (optional Hamamatsu camera with analog preprocessor), PC-AT Computer with HaSoTec Framegrabber FG-30 (ISA), HaSoTec SM-20 3-channel stepping motor control, focus motor for Nikon, optional X-Y-scanning stage. |
| HCA-200 configuration (from 1999) |
| Nikon Eclipse, TV-camera (optional Hamamatsu camera with analog preprocessor), PC-AT Computer with HaSoTec Framegrabber FG-32 (PCI), HaSoTec SM-30 (until 2000). Current version: HaSoTec Framegrabber FG-34 (PCI), SM-40 4-channel stepping motor control, focus motor for Nikon, optional X-Y-scanning stage. |
| HCA-200 configuration (from 2003) |
| Nikon Eclipse, TV-camera (600 lines), PC-AT Computer with HaSoTec Framegrabber FG-34 (PCI), HaSoTec, SM-41 4-channel stepping motor control, focus motor for Nikon, optional X-Y-scanning stage. |
