# Methylene Blue- Laboratory grade



## Bioteacher (Sep 8, 2008)

Hello. I hope someone can answer this question. I've been getting some molding in my azureus eggs. I'm a Biology teacher, and I have on hand some laboratory grade powdered methylene blue (the bottle says 100%). I'd like to avoid buying the stuff from a fish store if I can dilute what I already have. Can anyone tell me the strength of what you are using from the fish store? I've read 2 drops per gallon, etc., but I need to know the strength of the "drops" you use. Or perhaps a way to eyeball how "strong" it should be? I'd like to use what I've got, but I don't want to kill the eggs.

Thanks-

Julie


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## Julio (Oct 8, 2007)

the powder mixture is way too strong in my opinion so i would dilute it about %50.


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## JL-Exotics (Nov 10, 2005)

Julio said:


> the powder mixture is way too strong in my opinion so i would dilute it about %50.



Julio, is this based on anything factual or just a guess?


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## beachbabe18509 (Oct 29, 2007)

This is what I came up with
A stock solution (3.7 mg/ml.) can be made by dissolving 1.4 grams of powder in 380 ml.s of water. In actual practice, most folks simply buy stock solutions. 



and I found that on this site

MethyleneBlue


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## Philsuma (Jul 18, 2006)

Meth Blue has a short shelf life and even shorter when used as a water / meth mix, no?


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## Rick H. (Feb 22, 2007)

Hi Julie,

This is a recipe for a stock methylene blue solution for use with living organisms:
Methylene blue - 1 g
NaCl - 0.5 g
Make up in 100 mL H2O
Use: For living organisms 

Once you make the stock solution, create a diluted solution to use on the eggs. To do this put 5 drops of the stock solution in 450 ml of water.

The powdered form and stock solution should be relatively stable, the diluted solution is less so. You may find other recipes for methylene blue solution, but be careful of those. Methylene blue is commonly used as a stain for dead material and you don't want to use those recipes for your eggs. I have been using the above recipe for more than a year and it works great.

Rick


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## Julio (Oct 8, 2007)

JL-Exotics said:


> Julio, is this based on anything factual or just a guess?


powder mixtures are much stronger because generally they are more concentrated, this has been my experience when i worked with it at the zoo and we never used full strength.


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## elmoisfive (Dec 31, 2004)

Julie,

Typically I dilute 2 drops of 2.3% stock solution into about 100-120 milliters of water and submerge the eggs half way. This is an intensely blue solution, much stronger than one would use as a preventative measure with fish tanks. However it does the trick and will not harm the eggs. For more aggressive molding I've doubled the concentration with no harmful effects.

Bill


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## JL-Exotics (Nov 10, 2005)

Julio said:


> powder mixtures are much stronger because generally they are more concentrated, this has been my experience when i worked with it at the zoo and we never used full strength.


Ah, I see. I was just a little confused by the opinion to dilute by 50%, wasn't really sure what that meant exactly.


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