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BioForum _ General Lab Techniques _ How to make a tetracycline solution

Posted by: slapolla Mar 25 2005, 09:40 AM

I am making at 5 mg/mL soln of Tetracycline, and am using EtOH per our most recent Molecular Cloning manual...but I am having trouble getting all of the solid dissolved. Should I be using 70 % ETOH? Any thoughts/suggestions would be appreciated!!

Posted by: matiascs Mar 25 2005, 12:56 PM

Ive made some Tet sol. a couple of times....be sure to use an analytical balance, and dissolve it in absolute ethanol (100%)....and shake it up like theres no tomorrow...itll take a while but it will go into solution...
Do not autoclave...its ready for use....
Cheers





QUOTE (slapolla @ Mar 25 2005, 10:40 AM)
I am making at 5 mg/mL soln of Tetracycline, and am using EtOH per our most recent Molecular Cloning manual...but I am having trouble getting all of the solid dissolved. Should I be using 70 % ETOH? Any thoughts/suggestions would be appreciated!!
*

Posted by: chandima Mar 29 2005, 03:04 AM

i agree with matiascs. I do the same
chandima

Posted by: dreamchaser_jc Jan 29 2009, 05:54 AM

People,

Err... How do we know when to use water or ethanol? We have so much stocks here that I have yet to prepare any antibiotic solutions.

Posted by: mdfenko Jan 29 2009, 07:53 AM

QUOTE (dreamchaser_jc @ Jan 29 2009, 09:54 AM) *
People,

Err... How do we know when to use water or ethanol? We have so much stocks here that I have yet to prepare any antibiotic solutions.


you use that in which it is soluble and stable and will not interfere with your purpose.

Posted by: dreamchaser_jc Jan 29 2009, 04:25 PM

QUOTE (mdfenko @ Jan 30 2009, 12:53 AM) *
QUOTE (dreamchaser_jc @ Jan 29 2009, 09:54 AM) *
People,

Err... How do we know when to use water or ethanol? We have so much stocks here that I have yet to prepare any antibiotic solutions.


you use that in which it is soluble and stable and will not interfere with your purpose.


Alright, got it!

Posted by: molgen Feb 12 2009, 09:24 AM

According to Lab-facts (Roche) make the stock in Et-OH and the dilutions in liquid culture.

Posted by: phage434 Feb 13 2009, 08:42 AM

I believe the confusion is that two forms of tetracycline are marketed, the compound, and its hydrochloride. Tetracycline is soluble in EtOH, but not water. Tet-HCl is soluble in water. Dissolving Tet-HCl in 50% EtOH is what we like, since it keeps the solution at -20C liquid.

Posted by: hanming86 Feb 15 2009, 08:34 AM

QUOTE (phage434 @ Feb 13 2009, 08:42 AM) *
I believe the confusion is that two forms of tetracycline are marketed, the compound, and its hydrochloride. Tetracycline is soluble in EtOH, but not water. Tet-HCl is soluble in water. Dissolving Tet-HCl in 50% EtOH is what we like, since it keeps the solution at -20C liquid.


And from my experience Tet-HCL is not as soluble in Ethanol compared to water. Tet-HCL in Absolute EtOH is quite crappy in term of solubility.

Posted by: DNA Mar 12 2009, 07:22 PM

Hi Guys,

I f we make tetracycline stock solution i absolute or 100% ethanol instead of water, dont u think that ethanol is dangerous/killer for E.Coli cells?

Yes i agree that not all tetracyline get dissolved , but i am still using it anyways by giving it a bit vortex.

Please advise.

Thanx.

Posted by: phage434 Mar 12 2009, 08:34 PM

The 1000x dilution you do when adding the stock to the medium makes the EtOH in the medium inconsequential.

Posted by: DNA Mar 12 2009, 08:57 PM

QUOTE (phage434 @ Mar 13 2009, 03:04 PM) *
The 1000x dilution you do when adding the stock to the medium makes the EtOH in the medium inconsequential.



Thank you very much phage434. I did not know about it that we can do it.

We have got Tet-Hcl and i would like to prepare it your way i.e 50% ethanol so it will remain in liquid form and no freeze thaw.

Cheers

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