Re: Starch in microalgae

From: Richard Haugland (richard.haugland@probes.com)
Date: Thu Feb 07 2002 - 17:04:48 EST


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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