The following image comes from this resource and is labelled to show which structure is which (Walter Dioni, http://microscopy-uk.org.uk/mag/indexmag.html?http://microscopy-uk.org.uk/mag/artfeb04/wdstem.html):
ep = skin of the stem – col = colenchyma – par = cortical parenchyma (colenchyme + parenchyma form the cortex) –cb = cambium interfasciculaire – Paq.vasc. = package or vascular bundle formed by the phloem (ph) and the xylem (xy). Later it will be seen with more details – moelle, the central cylinder of parenchyma (the pith). Cambium plus pith form a central cylinder: the stele. The raphides are oxalate of calcium needles secreted by some cells. Here, the edges of the razor blades have cut an epithelial cell full of raphides throwing them on the cuted surface
I think the dark brown/black areas between cells in my photos below are vascular bundles seen end on, with the thick spiral supporting structure shown in the photos in my photos of the vertical section seen at the link above acting to block out light when seen end on. I can not identify raphides in the pictures below but I think I may have seen them in another post – see http://roslistonastronomy.uk/plant-stem-from-kitchen
My photos from today:
x10 objective, bright field:
x20 objective, bright field:
x32 objective, bright field:
x10 objective bright field crossed polarisation – varying rotation angle of one filter (below):
I tried adding in the Optivar into the optical train today. This is an additional magnifying lens that does the same job as a Barlow lens on a telescope. In a previous post, I noted that this particular Optivar suffers from extensive delamination so today was my first chance to find out if this is a significant issue and what difference an Optivar makes on my microscope. When I purchased it and it arrived and I found that it had the delamination I managed to get a massive discount so I am not concerned if it isn’t that good but it would be nice if it worked!
The following two pictures show an image using 32x objective bright field with and without Optivar of the cell boundary area on the tulip stem from the previous post.
The Optivar loses some of the sharpness of the image and with higher power lenses in the Optivar (it provides 1x, 1.25x, 1.6x and 2x lens – photo below with 1x lens to compare with photo without Optivar) the image is not as well focused – sadly the delamination does affect the image. Mind you, the image is not that bad and it should still be helpful for some projects.
I bought my wife some tulip cut flowers last week – an ideal place to obtain a short section of stem. The biggest problem was finding a fresh sharp blade to cut it. Ideally, a new razor blade would do the job but I did not have one to hand!
An excellent resource which discusses what can be found in such sections can be read at http://microscopy-uk.org.uk/mag/indexmag.html?http://microscopy-uk.org.uk/mag/artfeb04/wdstem.html
In particular, see the image that author has published on that page of the spiral reinforcing structures in the vascular bundles of the stem – you can see these spiral reinforcing structures, cell walls, chloroplasts in my images below – although there are also linear artifacts from my cuts/folding tissue as I cut (basically it goes crinkly – although I floated the section on a drop of water on the slide to try and smooth this out. It is for this reason that I have not published any images of the Helicon Focus 3D depth maps – as the crinkling dominates the depth maps).
The following photos show a piece of plant stem I cut up from a pot in our kitchen this evening. I don’t know what the plant was. It shows may chloroplasts and cell walls.
x20 bright field:
x20 objective Phase Contrast I annulus:
x32 objective Phase Contrast I annulus:
The following two photos are both taken using the x32 objective and phase contrast I annulus. The long thin features look like bacteria but they did not move so I wonder if they come from the plant? I wonder if they might be raphides. Raphides are oxalate of calcium needles secreted by some cells. Here, the edges of my blade may have cut an epithelial cell full of raphides throwing them on the cut surface, in a similar way to that experienced by Walter Dioni in his post on http://microscopy-uk.org.uk/mag/indexmag.html?http://microscopy-uk.org.uk/mag/artfeb04/wdstem.html
This sample was collected from our garden 7 days ago and kept in an open jar of water.
The contents of the jar had separated into a top layer of moss floating on the top, an intermediate layer of very cloudy water and a bottom layer of debris on the bottom of the jar. I have tried to sample all three layers in the pictures below.
x20 objective bright field sample from bottom of jar – debris layer. This shows large numbers of bacteria.
x32 objective bright field bottom debris layer:
Moss 7 day culture bottom jar layer video x32 objective Phase I annulus:
x20 phase contrast I debris layer bottom jar:
x32 objective phase contrast I debris layer jar:
x20 objective phase contrast I cloudy liquid layer between debris on bottom and floating moss – I am not convinced that this is phase contrast even though I labelled it as such – looks like bright field to me now:
x20 bright field liquid layer between debris and moss – video:
x20 bright field one single moss plant from the floating moss on top of the jar. If you look carefully you can see hundreds of bacteria surrounding this plant:
The following pictures are from my attempts today to try oblique illumination on the specimen using a swan-neck halogen illuminator – light shone upwards at bottom of slide obliquely. Photos below are compared to others using bright field with 10W retro-diode.com illuminator – all with Zeiss Standard microscope.
The sample is a piece of plant leaf cut from house plant in our kitchen.
The oblique illumination gives dark field effects – I picked this technique up from Micscape microscope forum (http://microscopy-uk.org.uk/mag/indexmag.html), although my oblique illuminator has currently a very red light so white balance needs to be corrected.
I have used curves function in GIMP2 to remove parts of curve without data from top and bottom of curve and in the image with lot of blue to enhance some parts curve in-between (but not done that on other images).
The pictures show swirls of cells in circular patterns and veins along the leaf.
Zeiss Standard microscope with external halogen swan-neck illuminator:
x10 objective, bright field:
x10 objective, oblique illumination, with white balance correction:
x40 objective, bright field:
x40 oblique illumination, without white balance correction:
This leaf fell off our orchid plant today – so I took the opportunity to look at this under the Zeiss IM microscope using the x4 objective.
You can see the cells that form the surface of the leaf together with the pores through which water vapour escapes as part of the plant’s water cycle. Within the cells, organelles can be seen. Around the cells are thick cell walls.
Note for this photograph, I turned the photo into greyscale and then re-colourised it (changed to RGB then added colour in GIMP2) to turn it green to reflect the colour of the leaf. No other processing applied to the image.
Magnification calculated as MikrOkular camera & screen magnification factor 68 (=4300/63 – see previous post) x 4 (4x objective) = (4300/63=68)x4= 272x magnification on screen.