Tamoxifen administration to mice: Difference between revisions
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[[Image:Tamoxifen(OH).gif|right|thumb|150px|chemical structure of tamoxifen and 4-hydroxy-tamoxifen]] | |||
Tamoxifen is | One of the uses of [[tamoxifen]] in the lab is the activation of enzymes deactivated via an estrogen-binding domain, like Cre-ER<sup>T</sup> (Cre-LBD). Tamoxifen is an estrogen analogue that binds with higher affinity than estrogen to altered estrogen binding domains. There are several ways to administer tamoxifen to mice each with advantages and disadvantages. If precise dosage is not paramount, administration via food is the gentlest to the animal. Keep in mind that induction varies depending on Cre and target genes. | ||
== | == Tamoxifen administration via chow == | ||
* <font color=green>'''pro''': less labour-intensive and less stressful for the animals</font> | |||
* <font color=red>'''con''': dosage depends on eating behaviour; induction may take longer then IP</font> | |||
[ | * tamoxifen formulation in typical mouse food pellets have just become commercially available ([http://www.harlaneurope.com/FFcms/klanten/HAR/index.php?select=3.02.04 Harlan Teklad CRD TAM400/CreER]) | ||
* 400 mg tamoxifen citrate per kg food irradiated pellets | |||
* dosage is based on Kiermeyer et al. 2007 "Optimization of spatiotemporal gene inactivation in mouse heart by oral application of tamoxifen citrate." (PMID 17216603) where efficient induction took 4 weeks. It appears that speed of induction is highly dependent on target genes (LoxP insertion sites) and can be as short as days. | |||
=== | == Tamoxifen administration via drinking water == | ||
* <font color=green>'''pro''': less labour-intensive and less stressful for the animals</font> | |||
* <font color=red>'''con''': dosage limited by low solubility of tamoxifen in water; dosage depends on drinking behaviour; induction may take longer then IP</font> | |||
#dissolve 100mg tamoxifen in 100µl pure ethanol (10mg/100µl = 100mg/ml tamoxifen) | #dissolve 100mg tamoxifen in 100µl pure ethanol (10mg/100µl = 100mg/ml tamoxifen) | ||
#dilute 100-200x in distilled water to final concentration of 1-0.5mg/ml | #dilute 100-200x in distilled water to final concentration of 1-0.5mg/ml | ||
| Line 44: | Line 25: | ||
compare Gail et al 1999, PMID 10547390, p355: treatment of mice | compare Gail et al 1999, PMID 10547390, p355: treatment of mice | ||
== Tamoxifen administration using a feeding needle == | |||
* <font color=green>'''pro''': dosage more precise than feeding and drinking (less than IP)</font> | |||
* <font color=red>'''con''': time consuming; stressful for animals</font> | |||
final concentration: 100µg/µl ~ '''1mg/10µl''' | |||
#100 mg Tamoxifen-free base (Sigma, T5648) was suspended in 100 μl Ethanol and solved in 900 μl peanut oil (Sigma). This 10 mg/100 μl tamoxifen solution was shaken rigorously at 55°C (Tamoxifen precipitates at RT) and divided in aliquots of 50 μl (1 daily dose = 5mg). Store at -20°C. | #100 mg Tamoxifen-free base (Sigma, T5648) was suspended in 100 μl Ethanol and solved in 900 μl peanut oil (Sigma). This 10 mg/100 μl tamoxifen solution was shaken rigorously at 55°C (Tamoxifen precipitates at RT) and divided in aliquots of 50 μl (1 daily dose = 5mg). Store at -20°C. | ||
# | #heat to 37°C before administration. Verify that tamoxifen is properly dissolved. | ||
# | #feed orally to mice with a feeding needle. Fix the mice at their neck and ridge so that the belly is directed to the floor. Hold the mouse tightly so that it can not move the head, but not too tight to avoid choking. Carefully introduce the feeding needle in the mouth behind the tongue (max. 1 cm). It is helpful to mark 1 cm on the needle with an edding pen in order to see how deep you have inserted the needle. | ||
# | #slowly introduce 50 μl of the tamoxifen solution with the syringe; assure swallowing; | ||
#e.g. repeat this procedure for 5 days once a day (efficiency of induction depends on Cre and transgene; determine your own dosage) | |||
(protocol: Stefan Glaser) | (protocol: Stefan Glaser) | ||
see also Metzger and Chambon, 2001, PMID 11327805, p73 | |||
== Tamoxifen administration by intraperitoneal injection == | |||
* <font color=green>'''pro''': reliable dosage</font> | |||
* <font color=red>'''con''': probably the most stressful method for the mouse; requires proficient handler</font> | |||
== See also == | == See also == | ||
* [[Tamoxifen|Tamoxifen - chemical information, mechanism of action, ER-deactivated fusion enzymes, stability & storage]] | |||
* [http://en.wikipedia.org/wiki/Tamoxifen Tamoxifen in Wikipedia] | * [http://en.wikipedia.org/wiki/Tamoxifen Tamoxifen in Wikipedia] | ||
* [http://ptcl.chem.ox.ac.uk/MSDS/HY/4-hydroxytamoxifen.html material safety 4-hydroxytamoxifen] | * [http://ptcl.chem.ox.ac.uk/MSDS/HY/4-hydroxytamoxifen.html material safety 4-hydroxytamoxifen] | ||
* [http://www.urmc.edu/ucar/manual/drug.htm Guidelines for various methods of fluid administration] by Rochester Medical Center | |||
* [http://www.bu.edu/research/compliance/lacu/lacf/sop/injection-techniques/intraperitoneal.shtml Intraperitoneal injection into the mouse] by Boston Uni | |||
* [http://www.ahwla.org.uk/site/tutorials/BVA/BVA05-Mouse/Mouse.html Mouse restraining and injection] by AHWLA including a video | |||
[[Category:Protocol]] | |||
[[Category:In vivo]] | |||
[[Category:Mouse]] | |||
Latest revision as of 08:09, 20 January 2010
| back to protocols | ||
.gif)
One of the uses of tamoxifen in the lab is the activation of enzymes deactivated via an estrogen-binding domain, like Cre-ERT (Cre-LBD). Tamoxifen is an estrogen analogue that binds with higher affinity than estrogen to altered estrogen binding domains. There are several ways to administer tamoxifen to mice each with advantages and disadvantages. If precise dosage is not paramount, administration via food is the gentlest to the animal. Keep in mind that induction varies depending on Cre and target genes.
Tamoxifen administration via chow
- pro: less labour-intensive and less stressful for the animals
- con: dosage depends on eating behaviour; induction may take longer then IP
- tamoxifen formulation in typical mouse food pellets have just become commercially available (Harlan Teklad CRD TAM400/CreER)
- 400 mg tamoxifen citrate per kg food irradiated pellets
- dosage is based on Kiermeyer et al. 2007 "Optimization of spatiotemporal gene inactivation in mouse heart by oral application of tamoxifen citrate." (PMID 17216603) where efficient induction took 4 weeks. It appears that speed of induction is highly dependent on target genes (LoxP insertion sites) and can be as short as days.
Tamoxifen administration via drinking water
- pro: less labour-intensive and less stressful for the animals
- con: dosage limited by low solubility of tamoxifen in water; dosage depends on drinking behaviour; induction may take longer then IP
- dissolve 100mg tamoxifen in 100µl pure ethanol (10mg/100µl = 100mg/ml tamoxifen)
- dilute 100-200x in distilled water to final concentration of 1-0.5mg/ml
- use 1% ethanol in distilled water as a negative control
- replace water in drinking bottles with tamoxifen solution; let mice drink at will
compare Gail et al 1999, PMID 10547390, p355: treatment of mice
Tamoxifen administration using a feeding needle
- pro: dosage more precise than feeding and drinking (less than IP)
- con: time consuming; stressful for animals
final concentration: 100µg/µl ~ 1mg/10µl
- 100 mg Tamoxifen-free base (Sigma, T5648) was suspended in 100 μl Ethanol and solved in 900 μl peanut oil (Sigma). This 10 mg/100 μl tamoxifen solution was shaken rigorously at 55°C (Tamoxifen precipitates at RT) and divided in aliquots of 50 μl (1 daily dose = 5mg). Store at -20°C.
- heat to 37°C before administration. Verify that tamoxifen is properly dissolved.
- feed orally to mice with a feeding needle. Fix the mice at their neck and ridge so that the belly is directed to the floor. Hold the mouse tightly so that it can not move the head, but not too tight to avoid choking. Carefully introduce the feeding needle in the mouth behind the tongue (max. 1 cm). It is helpful to mark 1 cm on the needle with an edding pen in order to see how deep you have inserted the needle.
- slowly introduce 50 μl of the tamoxifen solution with the syringe; assure swallowing;
- e.g. repeat this procedure for 5 days once a day (efficiency of induction depends on Cre and transgene; determine your own dosage)
(protocol: Stefan Glaser)
see also Metzger and Chambon, 2001, PMID 11327805, p73
Tamoxifen administration by intraperitoneal injection
- pro: reliable dosage
- con: probably the most stressful method for the mouse; requires proficient handler
See also
- Tamoxifen - chemical information, mechanism of action, ER-deactivated fusion enzymes, stability & storage
- Tamoxifen in Wikipedia
- material safety 4-hydroxytamoxifen
- Guidelines for various methods of fluid administration by Rochester Medical Center
- Intraperitoneal injection into the mouse by Boston Uni
- Mouse restraining and injection by AHWLA including a video
