My New Microtome

Here you can discuss all microscopy-related accessories and equipment (microtomes, filters...)
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mrsonchus
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Re: My New Microtome

#61 Post by mrsonchus » Mon Aug 10, 2015 4:41 pm

billbillt wrote:Hi John,
I never get tired of viewing your photos... They are very pleasing to the eye with crystal clear sharpness!..
BillT
You are very kind, thank you. :)
John B

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Re: My New Microtome

#62 Post by Interference » Thu Mar 31, 2016 1:27 am

Nice posting John.
I have a few blades like that in with the cut-throat and rusty triangle which came in a box.
Could you do a snap some time of the holder? It may be possible to make such a thing.

One thing I can't tell is how the wax slices run away from the edge without snagging on something :?

I wouldn't be surprised if better quality Stanley knife blades could be used, if in a suitable holder, maybe stropped first. You can easily shave with them.
Could I use a candle as a test block, I wonder? Maybe there's a market for sections of string :lol:


I got your pm John, but don't seem to be able to answer, maybe I'm not deemed safe yet.
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Re: My New Microtome

#63 Post by mrsonchus » Thu Mar 31, 2016 7:55 pm

Interference wrote:Nice posting John.
I have a few blades like that in with the cut-throat and rusty triangle which came in a box.
Could you do a snap some time of the holder? It may be possible to make such a thing.

One thing I can't tell is how the wax slices run away from the edge without snagging on something :?

I wouldn't be surprised if better quality Stanley knife blades could be used, if in a suitable holder, maybe stropped first. You can easily shave with them.
Could I use a candle as a test block, I wonder? Maybe there's a market for sections of string :lol:


I got your pm John, but don't seem to be able to answer, maybe I'm not deemed safe yet.
Hi Inter' I'm not quite sure what you mean old chap... Which holder are you referring to? I may be missing something - apologies but are you referring to the rotary microtome and it's blades, holder etc? I'm afraid I don't follow what you mean Inter'.

:)
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Re: My New Microtome

#64 Post by Interference » Thu Mar 31, 2016 10:26 pm

Sorry JB, It's me that's nuts, I missed a page out, ie I was replying to page 1 - this image
download/file.php?id=2356

Shows some loose disposables, which I think are like some I have.

What does the clamp look like, and also too as well. what stops the wax catching on the step where the clamp hold the blade - thin arrow? Or is that a very sharp edge too? (I saw a puzzling clamp for a normal size razor blade, pic I'll try to get off the phone...)
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Re: My New Microtome

#65 Post by mrsonchus » Thu Mar 31, 2016 11:02 pm

Ah yes, I'm with you,
The wax sections don't catch on the blade-clamp at all, by design. A blade has two angles, the cutting angle is 'steeper' that the angle made with the parallel-sided blade-body - that actual cutting angle is just perfect to deflect the wax sections past the clamp's leading-edge which is 1mm below the blade's edge usually. It's no problem, if it were microtomes wouldn't work....

The replaceable-blade clamp on a microtome such as my rotary Shandon is an entire assembly that is part of the microtome proper.
shandon_microtome (4).jpg
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It's proprietary and costs a fortune.....

If you have an old machine that takes 'ordinary' steel blades (the large ones with a handle that need to be sharpened and maintained) there are purpose-made disposable-blade 'adapters' that fit as if they were a steel blade.

They're quite expensive (cheapest from India is about £150..) and I'm certain their manufacture is no real problem if you have the equipment and skills to make one - I 'made' one when exploring the principle of making one for my then rocking microtome - I simply stuck an ordinary razorblade to my steel knife (which needed sharpening or replacing for about £25!) with cellotape and got a few perfectly-cut sections, thus telling me immediately that the blade was by far the main criterion for good sectioning and left me intending to make a 'proper' holder.
However then I came across my Shandon rotary for a ridiculously reasonable price and bought that, which uses the absolutely superb 'low-profile' replaceable blade system. The rest as they say is history.

Having said that I seem to remember that Brunel Microscopes sell them (the adapters to take replaceable blades) and the blades for that matter....... see here -> http://www.brunelmicroscopes.co.uk/micr ... ories.html

Here's a snapshot off-screen,
brunel blade holder.JPG
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I suppose if I had a rotary that took this type of holder I'd be willing to pay this amount for one, as it's not a huge amount and the disposable blade system is in my experience fantastic in use.

Good luck, in my posts are details of the trial I refer to with the 'stuck-on' blade - viewtopic.php?f=6&t=1109&hilit=happy+accident - it's quite amazing really what can be achieved with stick-tape and a razorblade! :D
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Re: My New Microtome

#66 Post by Interference » Fri Apr 01, 2016 12:46 am

Thanks
Too expensive!

I think we're saying that the wax jumps over any gap, like this.

If it's flexible enough to run over your sellotaped razor blade, that makes sense.

It leaves an interesting potential issue (for DIY blade holder makers) at the arrowed point. You really wouldn't want that rubbing, as I've shown it.

I wonder how critical the angle of attack of the blade to specimen, is.

I've just today bought a blade for an AO, for ten bucks. I can't really see why it couldn't be got working in a rocker, as long as it goes in the slot between the thumbscrews.

Next time you take the replaceable blade out of your machine's holder, I'd appreciate a pic to show how the blade is held. I assume it's just little pegs?

Another possiblility could be a Stanley knife blade, sitting in a scraper/holder upside down. They're held by the angled ends. Scraper/holder could also be used while sharpening the blade.
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Re: My New Microtome

#67 Post by Interference » Fri Apr 01, 2016 12:54 am

Phone pictures of a blade holder.
I should have bought the microtome just for the holder!
I'm not certain if it's for the single edged blades, the slot which might fit the back edge, doesn't look in quite the right place:
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Re: My New Microtome

#68 Post by mrsonchus » Fri Apr 01, 2016 4:27 am

Give it a try and see how it goes, you've got to start somewhere... :) Let us know how it goes.
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Re: My New Microtome

#69 Post by Interference » Fri Apr 01, 2016 8:53 am

I have to make a wax block holder as well :(
I have the "pepper pot" thing but not the popular one with a screw clamp.

Would ordinary candle "work" or is the wax different?
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Re: My New Microtome

#70 Post by mrsonchus » Fri Apr 01, 2016 10:58 am

Interference wrote:I have to make a wax block holder as well :(
I have the "pepper pot" thing but not the popular one with a screw clamp.

Would ordinary candle "work" or is the wax different?
Hi, I've the very same hand-microtome as you, from Brunel M also. I've a post in this forum where I 'develop' a method of using this microtome with wax using internal, split, lined, cylindrical moulds.
If you look through my posts you'll find a detailed thread dealing with this, including video...

Here are two of my short videos re this topic, there are more, the first is of the (wax) mould I made to fit the hand-microtome,


Here's how I use this microtome, similar to your musing re the blade's angle of attack, I use the blade in the manner of 'Madame Guillotine' - i.e. obliquely..


Have a look for my threads and you'll find lots of details therein. Hope this helps a little. :)
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Re: My New Microtome

#71 Post by Interference » Wed Jun 08, 2016 6:38 pm

Please excuse the hijack. I'm hoping to connect with someone about a Leitz 1512, & thought someone may be following this thread.
I've started a New Post.
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Re: My New Microtome

#72 Post by billbillt » Wed Jun 08, 2016 8:37 pm

Hi John,
I am sure you have posted about it, but does the Shandon use replaceable blades?.. If so how long does one last?..

BillT

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Re: My New Microtome

#73 Post by mrsonchus » Wed Jun 08, 2016 10:49 pm

billbillt wrote:Hi John,
I am sure you have posted about it, but does the Shandon use replaceable blades?.. If so how long does one last?..

BillT
Hi there Bill, yes the Mighty Shandon uses replaceable blades - 'low profile' are the de-facto std I would say - they're thinner (from 'top to bottom' that is) than the 'high profile' and each type (i.e. low and high) has a different blade-carrier. You need to ensure that any microtome you may consider has the facility to use 'replaceable low-profile blades' such as the ones I use - you MUST make sure of this - if you don't a carrier is very expensive indeed...

How long do they last - pretty long - but then 'how long's a piece of string?'. At first as I started as a total novice I was terrified of using up the precious blades too quickly, then I would possibly use about 2 a week with constant practicing and some hideous 'blade-mangling' randomly occurring... :oops:

Then within about 2 weeks I improved to the extent of 'using them properly' and soon discovered 2 things in the following order over another 2-4 weeks or so:
1) you need to have a 'set' of 'active blades' on the go of say 3 blades - 1 for 'roughing', 1 for 'polishing and quick sectioning/practice' and another for 'serious section time' - when all emphasis was on quality of section after roughing and polishing the wax-block's cut surface. I simply mark my active blades with a permanent marker as for example 'E12' for the 12th blade used from my 'Edge' brand blades etc...
2) as you become competent you soon realise that the only way to achieve a very high standard of section is to use a blade in very good condition, e.g. no nicks, no wax on the blade - both of these will inevitably score your sections and you will feel the need to weep & wail as you struggle to make sense of why it happened! :D

The good news - usage rate drops dramatically and quickly as you progress - I now use about 1 new blade per 2 sessions of sectioning, during which I will make anywhere between about 20 and 200 sections, with maybe a dozen 'premium quality' sections if I'm working on something I consider critical... The blades at full price are about £80-£120 for 50 - not much when you consider how few you use - almost irrelevantly low cost really.

But - they are often sold on e-bay unopened and brand-new for far less than this! I always have a quick check about once a week to see if any are up for sale. I've paid as little as £16 delivered for a brand new box of 50 - the most I've paid is £30! I've now such a good and cheaply-bought stock of blades that I won't need any for about 3 years I'd say, maybe longer! Total cost to me for my 'stash' has been about £80 for 4 boxes (brand spanking new and full - still in the sealed wrapper) of 50 - and I've still about 3 1/2 boxes left!

I hope this helps - please note my advice carefully if you're considering the acquisition of a microtome similar to my rotary Mighty-Shandon - don't even consider one that doesn't have a carrier (blade) that takes replaceable (sometimes called 'disposable') low-profile blades, for example the 'Shandon S35' blades that you may see in my posts re the Mighty Shandon...

Let me know how you get on! Ask-away if you need any advice at all re microtomes old chap, I'm always pleased to help. :)

p.s. last time I checked a few days ago there were new boxes offered for £60 - more than you will often need to pay, but still a complete bargain - and the size of packaging make postage trivial I think!
John B

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Re: My New Microtome

#74 Post by billbillt » Thu Jun 09, 2016 5:52 am

Hi John,
Thanks so much for your quick and informative reply.. I have just been agonizing over spending the cash on a microtome.. I truly enjoy following your exploits with one!..

The Best,
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Re: My New Microtome

#75 Post by Interference » Thu Jun 09, 2016 8:02 am

Question to 'tomists, which type is suitable for what?

This is a naive question from someone who has a few but not used them in anger.
Oversimplifying, there's the Hand variety, then Cambridge rocker type then some heavy rotaries such as the Shandon or Leitz. (Ignoring sledge, cryo, vibro, ultra)
If we're thinking of botanical or insect specimens, where does the suitablitity of the cheaper ones decline ?

Other than consistency and speed, you get thinner slices as you spend.
You can adjust the blade angle on the Rotaries (Leitz anyway) is that important ?

There's an overview article here which describes what they are rather than finer info on what they're used for
(the Numbering (blue) links to pictures etc, but they're out of line)

http://www.slideshare.net/vikas25187/mi ... -of-razors
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Re: My New Microtome

#76 Post by mrsonchus » Thu Jun 09, 2016 2:49 pm

Interference wrote:Question to 'tomists, which type is suitable for what?
....deleted for brevity
A very quick reply Inter' - I'm short of time right now,

A) The hand-microtome (see my post using it with 'carrot clamp' or with wax cast around specimen..) - OK for thicker and 'quick look' sections of live (fresh) tissue - produces sections a little too thick and uneven for permanent mounting.

B) 'rocking mcicrotome' AKA 'Cambridge rocker' - see my posts re use of this also. Good for 'proper' wax-embedded tissue that has been fully processed in exactly the same way as is required for the rotary microtomes such as my 'Mighty Shandon' 0325. These are very good indeed but require the use of a 'normal' steel microtome knife - and these quickly lose their edge and are then almost impossible to re-sharpen to their potential. It is possible to buy an 'adapter' to enable these to hold disposable blades but they cost (the adapters that is) about 2 1/2 times the cost of the rocking microtome!
Using the rocker without replaceable blades is simply Hell-on-Earth - you will in my experience never-ever- be able to get the sort of quality of section that a rotary using replaceable blades can give you. They also by the nature of their action produce slightly 'curved' sections that as laid flat will inevitably include stress bands which may or may not be noticeable - probably not I think - this may be merely a theoretical shortcoming... They do not retract the blade away from the block on their return stroke as many (including the Mighty Shandon) do - a very useful feature as this stops the blade catching or fouling the wax-block as it returns to the top of it's (cutting) stroke.

C) The rotary retracting microtomes - the best in the business for my application and pocket! They are amazingly good when used properly - my Mighty Shandon is able to produce perfectly cut sections from about 25µ right down to the design-limit of 1µ - and without making a fuss about it! Please again see my many posts re the Mighty Shandon and it's production of slides, including 1µ sections.

One small point - thinner is not always better - it depends on what the tissue is and what you intend to study with the sections cut.

For 'gross morphology' such as say the 'vernation' of leaves in an immature bud, thicker sections are best of between about 20µ and 12µ in my actual experience - see my 'emerging bud' posts...

For 'general morphology and anatomy' I use between about 10µ down to a minimum of about 6µ, for the study perhaps of cellular patterns across tissue such as a leaf for example...

For studies of say chromosomes or mitotic figures, or perhaps nuclei within pollen grains for example, I may go down to between about 5µ and maybe even 1µ to isolate chromosomes and intra-cellular structures without the need to preserve cell-wall patterns, as this will be too thin to keep those intact - no problem if that's not what you're targeting of course...

I hope this helps a bit - but no, thinner isn't always better - my most commonly cut section range is between about 10µ and 6µ for Botanical work. :)

oh yes, blade angle - nowhere near as influential on sectioning as every tome I read seems to say it is - I simply set the blade angle index to zero for the disposable blades (as the user-manual recommends) and carry on. True the angle can be altered if you have a block that is compressing (wrinkling parallel to the blade as it cuts) excessively or your wax is a little hard or soft, or if your section thickness/blade combination benefits from adjustment - but I've explored these factors and their interrelationship/s extensively and have found from practical experience that with well processed tissue and well cast blocks, in the hands of a competent microtomist, that the blade angle is barely relevant as anything away from the zero index...
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Re: My New Microtome

#77 Post by Interference » Thu Jun 09, 2016 3:16 pm

Brilliant answer, thanks John. I assume the Leitz chopper retracts on the up stroke, so perhaps I'll look at keeping that one if I can fettle it, and release a rocker.
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Re: My New Microtome

#78 Post by MicroInspector » Fri Jun 10, 2016 7:16 pm

Very interesting and the microscope is cool.
But How can machine shave as anything tiny and Itty-bitty bitty like a virus or microbe or bacteria?
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Re: My New Microtome

#79 Post by Interference » Fri Jun 10, 2016 8:14 pm

Methinks you don't, you use one of these in STED :)
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Re: My New Microtome

#80 Post by MicroInspector » Fri Jun 10, 2016 8:45 pm

But thing shaves off very thin l Ike tissue organs etc
Bacteria and viruses.
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Re: My New Microtome

#81 Post by Interference » Fri Jun 10, 2016 9:06 pm

:? Not sure what the question is... :?
Viruses are too small for a normal light microscope so you need something else, different techniques like confocal and STED, flourescence - 2 photon etc. The Focus of the beam(s) is much smaller than the thickness of the sample.

It's a fascinating subject, there are new techniques all the time. For a new thread really.
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