Range: ~2-4 µm
|Green algae Chlorella vulgaris
|de Grooth BG, Geerken TH, Greve J. The cytodisk: a cytometer based upon a new principle of cell alignment. Cytometry. 1985 May6(3):226-33. value is in abstract 1st paragraph. Range is on p.227 left column bottom paragraphPubMed ID3996137
|Abstract: "A new method is described for one-dimensional alignment of small particles such as biological cells. A drop of the particle suspension is spread out on a flat disk or plate equipped with V-shaped grooves such as are present on a gramophone disk. After drying, the particles are located on the bottom of the grooves and are thus aligned in a one-dimensional array. The new alignment procedure is demonstrated with a suspension of fluorescent polystyrene microspheres (diameter 3.8 µm) and a suspension of the unicellular algae chlorella vulgaris (diameter about 3µm). It appears that the alignment of cells and spheres is very good. When using microspheres, more than 95% of the particles in the grooves are located within ±2 µm of the centre line of the groove. Based upon this cell-alignment principle, a new cytometer, named the cytodisk, is proposed. The proposed system has a number of advantages over the flow cytometer, among which is the unique ability of relocating a previously measured cell for further measurement or visual examination. A prototype of a cytodisk, developed for initial test measurements, was built in the researchers' laboratory. The apparatus, constructed from a record player and ordinary long-playing records, uses a simple mechanical tracking system and a single optical fiber for fluorescence excitation and detection." See fig. 7-9 in article
|P.227 left column 4th paragraph to bottom paragraph: "Particle Alignment in V-Shaped Grooves: The particle alignment principle (see Fig. 1) was tested with a suspension of fluorescent microspheres (3.8 µm diameter). The results are shown by the photomicrographs of Figures 2 and 3, obtained with an epi-illumination microscope. The record grooves, which have a width of about 80 µm and a depth of about 40 µm, are dark in the picture. The bright lines between the grooves are caused by the reflection of the flat upper surface of the record. The microspheres are clearly seen as small bright spots in the middle of the grooves. When the microscope is used as a fluorescence microscope by inserting proper filters, only the green fluorescent particles are observed, indicating that the record material itself shows very little fluorescence when excited at about 480 nm. Similar results were obtained with suspensions of the unicellular algae chlorella vulgaris. These algae have a diameter of about 2-4 µm and show a relatively strong red autofluorescence due to chlorophyll a when illuminated with blue light." Size of other Chlorella: freshwater chlorella (size of 3 µm to 10 µm), marine chlorella (size of 2 µm to 6 µm). See Esteban et al. 2010 PMID 20970377 p.627 right column bottom paragraph: "Chlorella is also extremely common as a free–living alga in fresh waters, soils and sub–aerial habitats. The cells are 1.5 to 10 μm in diameter, they reproduce asexually by forming replicas of themselves (usually two to eight, sometimes up to 16 called autospores) that are then released when the cell wall breaks up (Fott and Novákova 1969)."
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