Tamoxifen Diets

for Inducible Cre-LoxP Systems

Diets with tamoxifen activate CreER

Tamoxifen-containing diets should be considered an option if you are using a model with Cre under the control of a mutated estrogen receptor. Harlan Laboratories Teklad Diets makes a variety of tamoxifen-containing diets customized to meet your research needs. We also make a variety of doxycycline-containing diets for tetO regulated Cre. If you have any questions, don't hesitate to contact a nutritionist.
 
With introduction of any experimental diet, careful observation of animal tolerance is recommended. Please consult your IACUC for recommended monitoring metrics.
 
Tamoxifen diet options 
A short list is included below, but keep in mind that we can produce something different, based on your needs. In these examples, Teklad Global 2016 is used as the base diet to provide a minimal phytoestrogen background.
    
 Diet CodeTamoxifen
mg per kg
diet		Daily Tamoxifen
mg per kg
body weight* 		Alternative
with
food coloring 
TD.07262**400
(citrate form)		40TD.09327    Red
TD.0769425040

TD.110069  Red
  TD.10893   Green

 

TD.0851850080

   TD.10296    Green

 

*Assumes 20-25 g body weight and 3-4 g intake
**Referred to as TAM 400
  • Our minimum order quantity is 3 kg, sufficient for feeding ~20 mice for 1 month.
  • Typical lead time is 2 weeks (4 weeks if irradiated).
  • Store diet refrigerated and plan to use within six months.

Gather the supplies
Tamoxifen is added to the diet as a tamoxifen-sucrose mixture prepared by the researcher. Work with a nutritionist to determine the amount of tamoxifen-sucrose mixture needed for your order. See our tamoxifen info sheet for suppliers and additional information about preparing the mixture.

When you have the mixture prepared and are ready to send it, please take a minute to complete a brief online form to ensure proper chain of custody:  Customer-Supplied Ingredient Form
 

Key points from literature
  • Length of treatment varies from 7 days2, 3, 4 to 6 weeks2; 4 week feeding is common1
  • Pure tamoxifen2,3,4 and tamoxifen citrate1,4 are both effective
  • Usual tamoxifen doses are ~40-80 mg per kg body weight per day
  • Typical inclusion for pure tamoxifen is 250 mg2 or 500 mg3,4 and for tamoxifen citrate is 400 mg1,4 per kg diet
  • Initial weight loss of 10% is reported1, 2, 4
     

Selected Tamoxifen References

1. Kiermayer C, Conrad M, Schneider M, Schmidt J, Brielmeier M. 2007. Optimization of spatiotemporal gene inactivation in mouse heart by oral application of tamoxifen citrate.Genesis 45:11-16.
 
2. Welle S, Burgess K, Thornton CA, Tawil R. 2009. Relation between extent of myostatin depletion and muscle growth in mature mice.Am J Physiol Endocrinol Metab.Oct;297(4):E935-40.
 
3. Koitabashi N, Bedja D, Zaiman AL, Pinto YM, Zhang M, Gabrielson KL, Takimoto E, Kass DA. 2009. Avoidance of transient cardiomyopathy in cardiomyocyte-targeted tamoxifen-induced MerCreMer gene deletion models.Circ Res 105:12-15.
 
4. Andersson KB, Winer LH, Mork HK, Molkentin JD, Jaisser F. 2010. Tamoxifen administration routes and dosage for inducible Cre-mediated gene disruption in mouse hearts.Transgenic Res 19:715-725.

If you have any questions regarding tamoxifen diets, please don’t hesitate to contact a nutritionist at askanutritionist@harlan.com. 

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