Gynoecium, Asarum canadense
This is part of an ovary in Gynoecium of Asarum canadense, or wild ginger from a transverse section. Under crossed polarizers, the calcium oxalate crystals in the outer ovary wall show distinct birefringence. The specimen was stained with safranin-O and fast green, and thus is not ideal for polarized light microscopy. That the densely stained safranin-O layer is bright in this image is intriguing. The underlying tissue displayed some birefringence in the H-E stained case. Thus, given the density of the safranin-O in this tissue, I suspect it is simply being back lit. I need to prepare an unstained specimen to investigate this further.
The protocol was as follows. Specimens fixed in FAA (formaldehyde, acetic acid, ethanol) 48 hr. Dehydrated in 35, 50, 75, 85, 95, 99 % IPA in water, 6 hours each min. Infiltrated in xylene saturated with Paraplast for 2 days, followed by 2 changes of melted Praplast for 2 hours each. Embedded in Paraplast. Sectioned on a Spencer 820 microtome at 11 micron. 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 on a Spencer 42 petrographic polarizing microscope using an original magnification of , using a Sony NEX 5N with a Leica MIKAS 1/3X adapter.
Gynoecium, Asarum canadense
This is part of an ovary in Gynoecium of Asarum canadense, or wild ginger from a transverse section. Under crossed polarizers, the calcium oxalate crystals in the outer ovary wall show distinct birefringence. The specimen was stained with safranin-O and fast green, and thus is not ideal for polarized light microscopy. That the densely stained safranin-O layer is bright in this image is intriguing. The underlying tissue displayed some birefringence in the H-E stained case. Thus, given the density of the safranin-O in this tissue, I suspect it is simply being back lit. I need to prepare an unstained specimen to investigate this further.
The protocol was as follows. Specimens fixed in FAA (formaldehyde, acetic acid, ethanol) 48 hr. Dehydrated in 35, 50, 75, 85, 95, 99 % IPA in water, 6 hours each min. Infiltrated in xylene saturated with Paraplast for 2 days, followed by 2 changes of melted Praplast for 2 hours each. Embedded in Paraplast. Sectioned on a Spencer 820 microtome at 11 micron. 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 on a Spencer 42 petrographic polarizing microscope using an original magnification of , using a Sony NEX 5N with a Leica MIKAS 1/3X adapter.