Measuring chromosomes on 1µ sections
Posted: Sat Mar 05, 2016 1:46 am
Hi all, nearly forgot about the 1µ sections cut a couple of days ago. I stained and mounted a few slides from these terrifyingly-thin sections, after ruining several or having them simply fly-away and stick irretrievably to the dog! Anyway they're needless to say a little tricky but not impossible to handle, and here are a few pictures of them stained with Toluidine-blue. They show chromosomes well in the ovule-tissue containing cells dividing in mitosis...
Here's part of a section that folded-over while mounting - this happens occasionally and whilst it's a bit of a pain, it does give an opportunity tho measure the thickness of the folded-over tissue and therefore the thickness of the section, as compared to that set with the 'Mighty Shandon' at the time of sectioning. In this case the sections were cut at a nominal 1µ set on the MS's dial! The thickness measured supports the fact that the MS has indeed faithfully sectioned at the absolute minimum of it's operating-range, that of a single, lonely, micron...
It can be seen also that at 1µ the walls of un-strengthened 'ordinary' cells, such as parenchyma for example, are a little bruised and battered by the 1µ cut.
This is no surprise to me and isn't important as I'm not targeting the overall morphology at this thickness (for that I would section at between about 6-10µ) rather discreet chromosomes and details of strengthened-tissue such as xylem-vessels, and to this end I'm quite pleasantly surprised by the fine details the 1µ has apparently given the slide.
Here then is a 1µ section showing chromosomes in varying stages of mitosis. The detail is fine but I can achieve a similar level of detail at a far easier-to-cut 4/5µ! This one's a section at 1µ through a xylem-vessel's reinforced walls and really does show fine details that would be more difficult but not impossible to achieve at say 5-10µ... I think the thinness of the sections is making focus with the camera more crisp, no stacking needed at 1µ I suspect.. Sorry to be brief with these but I've no time left tonight. I think the 1µ may have a limited use but is a good practice-run for the nerves and steadiness of technique! I suspect my favoured thicknesses will be between about 4 and 10µ as these have both given me superb results recently.
Back with some more adventures soon.
Here's part of a section that folded-over while mounting - this happens occasionally and whilst it's a bit of a pain, it does give an opportunity tho measure the thickness of the folded-over tissue and therefore the thickness of the section, as compared to that set with the 'Mighty Shandon' at the time of sectioning. In this case the sections were cut at a nominal 1µ set on the MS's dial! The thickness measured supports the fact that the MS has indeed faithfully sectioned at the absolute minimum of it's operating-range, that of a single, lonely, micron...
It can be seen also that at 1µ the walls of un-strengthened 'ordinary' cells, such as parenchyma for example, are a little bruised and battered by the 1µ cut.
This is no surprise to me and isn't important as I'm not targeting the overall morphology at this thickness (for that I would section at between about 6-10µ) rather discreet chromosomes and details of strengthened-tissue such as xylem-vessels, and to this end I'm quite pleasantly surprised by the fine details the 1µ has apparently given the slide.
Here then is a 1µ section showing chromosomes in varying stages of mitosis. The detail is fine but I can achieve a similar level of detail at a far easier-to-cut 4/5µ! This one's a section at 1µ through a xylem-vessel's reinforced walls and really does show fine details that would be more difficult but not impossible to achieve at say 5-10µ... I think the thinness of the sections is making focus with the camera more crisp, no stacking needed at 1µ I suspect.. Sorry to be brief with these but I've no time left tonight. I think the 1µ may have a limited use but is a good practice-run for the nerves and steadiness of technique! I suspect my favoured thicknesses will be between about 4 and 10µ as these have both given me superb results recently.
Back with some more adventures soon.