Freezing bath for frozen section

[gorillamunch]

I am interested in purchasing a freezing bath for the frozen section room of a community hospital.
I am looking for recommendations for either new or used equipment.
Thanks in advance.

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[LADoc00]

huh...where are you? Eastern Europe?

Modern cryostats have specimen bars that do the rapid freezing built in. I havent seen nor heard some use the term freezing bath since I was stationed in the basement of a Vet school many many years ago...

Leica CM1950 | Clinical Cryostat - Product: Leica Biosystems

 

[gorillamunch]

huh...where are you? Eastern Europe?

Modern cryostats have specimen bars that do the rapid freezing built in. I havent seen nor heard some use the term freezing bath since I was stationed in the basement of a Vet school many many years ago...

In my experience, when both the freezing bath and the cryostat freezing (even in the Leica CM1950) were available, the freezing bath was preferred.

 

[Daddydoc]

In my experience, when both the freezing bath and the cryostat freezing (even in the Leica CM1950) were available, the freezing bath was preferred.

I used a freezing bath during part of residency. I strongly prefer freezing bars. My tissue is more likely to stay where I want it and it is not as messy.

 

[Euchromatin]

I've used quite a few different techniques regularly - cryobath, the freezing bar inside newer cryostats, as well as the big metal bars with embedding molds/wells (I believe called "Precision Cryo-Embedding System"), all +/- cryospray.

If you are doing higher volumes of frozen sections, especially if you get a lot of specimens that need to be particularly carefully embedded (i.e. strips of skin/mucosa for margin status) the embedding bars are the way to go. You keep them in the cryostat all the time so they are cold and ready to go. Then you place the tissue directly into the base of the well, cover it with OCT and put the chuck over the back. Put the whole thing back into the cryostat and hit the back of the chuck with a little extra crospray. When you're ready, the whole thing pops right out if you tap the chuck gently with something heavy. In my opinion, this is the fastest and most precise/cleanest way of making frozen blocks.

I thought cryobaths were also fine (might even be a little faster), but you have to freehand making a base of OCT on the chuck, then put the tissue on top of that (doable, but not quite as neat) and I would also usually take the extra step of putting a coverslip on top of the tissue - both to press it flat and to prevent the OCT from bubbling while it in the cryobath. I haven't used one of these since residency and I seem to recall hearing even then that they would not be replaced if/when they finally broke because no one was making them anymore.

I am not a huge fan of the freezing bars that are in the cryostat itself - although it may be the particular models I have tried. I've noticed they seem more inclined to develop an ice crust from moisture vs the rest of the interior surfaces of the cryostat (would depend on your machine and maintenance though) and, even when there doesn't seem to be a moisture problem, I have had more issues with chucks getting stuck (on either the back of the chuck/mount and/or the top of the OCT tissue block, depending). They also seem to be the slowest at freezing tissue in my personal experience.

 

[LADoc00]

Okay clearly there are folks here making a fine art of getting something cold fast. I prefer the easy built in and...already there...way of doing it.
As an analogy:
Yah you can make those HUGE ball shaped ice cubes for your whiskey because they melt slower because of less surface area and all, but when you are at home after a long day and your wife looks good to go, you throw refrig dispensed ice in the bottom of any clean glass you can find, pour 4 fingers of Elmer T Lee and call it a day, right?

You guys are overthinking this me thinks.

 

[MOHS_01]

I've used quite a few different techniques regularly - cryobath, the freezing bar inside newer cryostats, as well as the big metal bars with embedding molds/wells (I believe called "Precision Cryo-Embedding System"), all +/- cryospray.

If you are doing higher volumes of frozen sections, especially if you get a lot of specimens that need to be particularly carefully embedded (i.e. strips of skin/mucosa for margin status) the embedding bars are the way to go. You keep them in the cryostat all the time so they are cold and ready to go. Then you place the tissue directly into the base of the well, cover it with OCT and put the chuck over the back. Put the whole thing back into the cryostat and hit the back of the chuck with a little extra crospray. When you're ready, the whole thing pops right out if you tap the chuck gently with something heavy. In my opinion, this is the fastest and most precise/cleanest way of making frozen blocks.

I thought cryobaths were also fine (might even be a little faster), but you have to freehand making a base of OCT on the chuck, then put the tissue on top of that (doable, but not quite as neat) and I would also usually take the extra step of putting a coverslip on top of the tissue - both to press it flat and to prevent the OCT from bubbling while it in the cryobath. I haven't used one of these since residency and I seem to recall hearing even then that they would not be replaced if/when they finally broke because no one was making them anymore.

I am not a huge fan of the freezing bars that are in the cryostat itself - although it may be the particular models I have tried. I've noticed they seem more inclined to develop an ice crust from moisture vs the rest of the interior surfaces of the cryostat (would depend on your machine and maintenance though) and, even when there doesn't seem to be a moisture problem, I have had more issues with chucks getting stuck (on either the back of the chuck/mount and/or the top of the OCT tissue block, depending). They also seem to be the slowest at freezing tissue in my personal experience.

Speaking as someone who does only frozen sections, I agree with the above. A mirrored aluminum bar with wells a shade smaller than the width of the slide, mostly kept in the cryostat, gives you the most cost effective option for good early cuts.

 

[gorillamunch]

I've used quite a few different techniques regularly - cryobath, the freezing bar inside newer cryostats, as well as the big metal bars with embedding molds/wells (I believe called "Precision Cryo-Embedding System"), all +/- cryospray.

If you are doing higher volumes of frozen sections, especially if you get a lot of specimens that need to be particularly carefully embedded (i.e. strips of skin/mucosa for margin status) the embedding bars are the way to go. You keep them in the cryostat all the time so they are cold and ready to go. Then you place the tissue directly into the base of the well, cover it with OCT and put the chuck over the back. Put the whole thing back into the cryostat and hit the back of the chuck with a little extra crospray. When you're ready, the whole thing pops right out if you tap the chuck gently with something heavy. In my opinion, this is the fastest and most precise/cleanest way of making frozen blocks.

I thought cryobaths were also fine (might even be a little faster), but you have to freehand making a base of OCT on the chuck, then put the tissue on top of that (doable, but not quite as neat) and I would also usually take the extra step of putting a coverslip on top of the tissue - both to press it flat and to prevent the OCT from bubbling while it in the cryobath. I haven't used one of these since residency and I seem to recall hearing even then that they would not be replaced if/when they finally broke because no one was making them anymore.

I am not a huge fan of the freezing bars that are in the cryostat itself - although it may be the particular models I have tried. I've noticed they seem more inclined to develop an ice crust from moisture vs the rest of the interior surfaces of the cryostat (would depend on your machine and maintenance though) and, even when there doesn't seem to be a moisture problem, I have had more issues with chucks getting stuck (on either the back of the chuck/mount and/or the top of the OCT tissue block, depending). They also seem to be the slowest at freezing tissue in my personal experience.

Speaking as someone who does only frozen sections, I agree with the above. A mirrored aluminum bar with wells a shade smaller than the width of the slide, mostly kept in the cryostat, gives you the most cost effective option for good early cuts.

Thank you for the suggestion. Would you please link me to a picture of the aluminum bar in action?

 

[gorillamunch]

I have a used $500 Neslab Histobath 2 being delivered. The patent ("patent US5452584A"; google search this text to see the patent) recommends 3M Performance Fluid PF-5060 as the freezing fluid, for which I have been quoted $750 per 14 lb bottle by MG Chemicals Ltd in Canada. Does anyone use this freezing bath? If so, what freezing fluid do you use? Thanks again everyone for your help.

 

[Euchromatin]

Thank you for the suggestion. Would you please link me to a picture of the aluminum bar in action?

I don't have any pictures of the system "in action"

If you want to see generally what it looks like:
Google "precision cryo embedding system"
Click on "Images" tab
Profit???