No warranties on this one but Calcofluor White M2R (Fluorescent brightener 28, Sigma) may work but staining may not be very specific. Lectins are another possible alternative. Biotech Histochem 1992 Mar;67(2):88-97 Block-surface staining for differentiation of starch and cell walls in wheat endosperm. Glenn GM, Pitts MJ, Liao K, Irving DW. Western Regional Research Center, USDA-ARS, Albany, California 94710. A staining technique for differentiating starch granules and cell walls was developed for computer-assisted studies of starch granule distribution in cells of wheat (Triticum aestivum L.) caryopses. Blocks of embedded caryopses were sectioned, exposing the endosperm tissue, and stained with iodine potassium iodide (IKI) and Calcofluor White. Excessive tissue hydration during staining was avoided by using stains prepared in 80% ethanol and using short staining times. The IKI quenched background fluorescence which facilitated the use of higher concentrations of Calcofluor White. Cell wall definition was improved with the IKI-Calcofluor staining combination compared to Calcofluor alone. The high contrast between darkly stained starch granules and fluorescent cell walls permitted computer assisted analysis of data from selected hard and soft wheat varieties. The ratio of starch granule area to cell area was similar for both wheat classes. The starch granule sizes ranged from 2.1 microns 3 to 22,000 microns 3 with approximately 90% of the granules measuring less than 752 microns 3 (ca. 11 microns in diameter). Hard wheat samples had a greater number of small starch granules and a lower mean starch granule area compared to the soft wheat varieties tested. The starch size distribution curve was bimodal for both the hard and soft wheat varieties. Three-dimensional starch size distribution was measured for four cells near the central cheek region of a single caryopsis. The percentage of small granules was higher at the ends than at the mid-section of the cells Adelina de la Jara wrote: > I am a new list member and use to look up this e-mail archive to solve my > questions. Now I would like to ask the list if anyone can suggest a good > fluorescent dye for monitoring starch accumulation in microalgae? > > Many thanks. > > Adelina de la Jara Valido > Instituto Tecnologico de Canarias > Dpto. de Biotecnologia > Pozo Izquierdo 35119 Santa Lucia, Gran Canaria, Spain > Tfno.: 0034 928 133290 > Fax: 0034 928 132830
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