Equisetum arvense epidermis
This is a transverse section through the stem of a Horse Hair (Equisetum arvense) showing the epidermis. The inner cell walls of the epidermis can contain silica. A polarized light image showing the effects of the silica is at: www.flickr.com/photos/14643312@N02/17732281416. Specimen collected along the Dowagiac River, 25 May 2015.
The protocol was as follows. Specimens fixed in FAA (formaldehyde, acetic acid, ethanol) 48 hr. Dehydrated in IPA at 35, 50, 70, 85, 91, 95, 99 %. Infiltrated with paraplast saturated xylene 48 hr followed by 3 Paraplast baths prior to embedding in Paraplast. Sectioned 7 um thick on a Spencer 820 microtome. Cleared in xylene, 5 min, 2X. Rehydrated in 99, 95, 80, 70 %IPA. Stained in Johansen's Safranin-O, Fast Green (24 hours in Safranin-O, 15 sec. in fast green). Cleared 2 X in xylene 10 min each and mounted with DPEX.
Photographed in bright field on a Spencer 42 petrographic microscope at original magnification 430X using a Sony NEX-5N and a Leica MIKAS 1/3X adapter.
Equisetum arvense epidermis
This is a transverse section through the stem of a Horse Hair (Equisetum arvense) showing the epidermis. The inner cell walls of the epidermis can contain silica. A polarized light image showing the effects of the silica is at: www.flickr.com/photos/14643312@N02/17732281416. Specimen collected along the Dowagiac River, 25 May 2015.
The protocol was as follows. Specimens fixed in FAA (formaldehyde, acetic acid, ethanol) 48 hr. Dehydrated in IPA at 35, 50, 70, 85, 91, 95, 99 %. Infiltrated with paraplast saturated xylene 48 hr followed by 3 Paraplast baths prior to embedding in Paraplast. Sectioned 7 um thick on a Spencer 820 microtome. Cleared in xylene, 5 min, 2X. Rehydrated in 99, 95, 80, 70 %IPA. Stained in Johansen's Safranin-O, Fast Green (24 hours in Safranin-O, 15 sec. in fast green). Cleared 2 X in xylene 10 min each and mounted with DPEX.
Photographed in bright field on a Spencer 42 petrographic microscope at original magnification 430X using a Sony NEX-5N and a Leica MIKAS 1/3X adapter.