Tragacanth

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spyder086
spyder086's picture
Tragacanth

Hi
I'm wondering if anyone has knowledge about Tragacanth gum for cryostat use. I'm working with mice hearts, and read a paper in which the authors stated that hearts were extracted, mounted in tragacanth (5%), then flash frozen in cool isopentene. Does anyone know if the entire heart needs to be covered in tragacanth (after orienting it properly), then flash frozen or... is the tragacanth just used to hold the heart in place, then it is covered by OCT, then frozen?
I'm reading different protocols which contradict each other, (ie: cover / don't cover the sample in tragacanth). I wrote to the authors, who weren't very helpful..
Thanks for your time.

Arvind Singh Pundir
Arvind Singh Pundir's picture
spyder086 wrote:

spyder086 wrote:

Hi
I'm wondering if anyone has knowledge about Tragacanth gum for cryostat use. I'm working with mice hearts, and read a paper in which the authors stated that hearts were extracted, mounted in tragacanth (5%), then flash frozen in cool isopentene. Does anyone know if the entire heart needs to be covered in tragacanth (after orienting it properly), then flash frozen or... is the tragacanth just used to hold the heart in place, then it is covered by OCT, then frozen?
I'm reading different protocols which contradict each other, (ie: cover / don't cover the sample in tragacanth). I wrote to the authors, who weren't very helpful..
Thanks for your time.

as i have read but not used, the tragacanth helps as supporting media and it should not be covered on to the tissue entirely rather is only used as a supportting media, a 7% tragacanth gum in water is used for that (measure 100 ml distilled water and add to plastic container containing 7 gm Gum Tragacanth) 5 grains Thymol as preservative and dissolve by manually stirring at room temperature it takes a time to dissolve.

excalibur
excalibur's picture
The gum is used for initial

The gum is used for initial orientation of the sample. After freezing, you should cover the exposed tissue with OCT to prevent freezer burn, if the specimen is to be stored and not sectioned right away. One should also add an ice chip to the container holding the specimen to keep the moisture level steady. Water can also be "pulled" from the OCT during storage.
 
OCT could also be used for the orientation step, so why use 2 different substances that could separate during sectioning?