LW Scientific Soil Food Web Epi-Fluorescence Microscope Kit

LW Scientific Soil Food Web Epi-Fluorescence Microscope Kit - Model # I4M-TN4A-IPL3, i4P-EPiL-485N & BVC-4K16-CMT3

There are two distinct uses for epi-fluorescent microscopy:

First, colonization of roots by mycorrhizal fungi is easy to see (Ames, R. and E. Ingham, 1984) as VAM fungi produce autofluorescent compounds at the interface of the arbuscular cell wall and the plant cell membrane. With gridded camera images, it is easy to see the percentage of the total root length occupied by active arbuscule colonization.

Count the number of grids in the root that have fluorescent arbuscules present and count the total grids looked at. Grids with fluorescent arbuscules divided by total grids with and without fluorescent arbuscules, multiplied by 100, gives percent colonization.

Work by John Moore and a second person back in 1999 showed that in grasses, 12% colonization gives measurable benefit to the plant, but 40% colonization allows all the benefits to be realized.

The second use for epi-fluorescent microscopy involves use of fluorescein diacetate (FDA, original paper by Bengt Soderstrom, around 1976, and should be in reference material on the website).

One application is to assess coverage of leaf surfaces, fruit, or bark by layers of organisms growing on those surfaces. Only the active organisms will take up the stain and fluoresce. Strips of the surfaces can be cut out, stained by placing the materials in fluorescein diacetate for 3 minutes, and the stain will be taken up and metabolized by active, growing cells. 

Placement of the leaf, bark, or fruit on a slide illuminated by the fluorescein wavelengths allows the percentage of the total plant surface where active organisms cover the surface to be assessed. Coverage around 70% of higher active bacteria and fungi will result in reduction of fungal and bacterial diseases on the leaves, wood, and fruit.

Coverage is the important factor so that disease organisms never reach the plant surface; foods allow germination of the spores or reproductive particles of the disease organisms to be consumed by the beneficial organisms first.

A second application of staining with FDA is to add the FDA to a dilution of soil, compost, extract, or tea for a 3-minute period of time, then add hot, molten agar, which will stop all cells from taking up more FDA.

The cells should be killed or at least slowed significantly. Place the sample in a well-slide, NOT a hemocytometer slide, however (see Ingham et al. 1985 for description and details), place the slide on the microscope and assess the number of active bacteria (stained yellow-green fluorescein color), the length of fungal hyphae stained the fluorescein color, and then assess total bacteria and total fungi using shadowing microscopy.

What's Included:

✓ i4 Trinocular Microscope with Infinity Plan Objectives

✓ Lumin Epi-Fluorescence Module

✓ BioVID HD 4K Microscope Camera