STZ Frequently Asked Questions
What is STZ?
Streptozotocin (STZ) is an alkylating agent that affects pancreatic islets, inducing diabetes in mice. The males of various strains are differentially susceptible to developing diabetes: FVB/NJ (001800), BALB/cJ (000651), and A/J (000646) males are resistant; C57BL/6J (000664) males are moderately susceptible; and NOD/ShiLtJ (001976) and CBA/J (000656) males are highly susceptible. NOD-congenic strains like NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG; 005557) and NOD.CB17-Prkdcsci/J (NOD scid; 001303) are also highly susceptible. We have developed a multiple low dose STZ protocol that induces diabetes in C57BL/6J, NSG and NOD scid males.
What is the JAX protocol for STZ-induced diabetes?
- Six-week-old C57BL/6J (000664, B6) or NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (005557, NSG) or NOD.CB17-Prkdcscid/J ( 001303, NOD scid) males are individually marked, weighed, and their baseline blood glucose levels determined (OneTouch Ultra monitor)
- Mice receive daily IP injections of 50 mg STZ/kg body weight (the most effective dose for B6 males) or 40 mg STZ/kg body weight (for NSG & NOD-scid males) for five consecutive days; age-matched controls receive buffer–only injections
- Because mice metabolize STZ for at least 24 hours post-injection, they are housed in disposable cages with appropriate absorbent bedding and food and water ad libitum
- Mice are moved to clean cages at least 24 hours after the final injection
- The mice are observed daily and tested the week following injections. Only mice with blood glucose exceeding 250 mg/dL are placed into inventory.
How soon and late after being STZ-injected can mice be shipped?
C57BL/6J mice are available to ship as soon as one week after the final injection, when they are 8 weeks of age. An inventory is maintained at 8 & 9 weeks of age. NOD-scid & NSG mice respond more rapidly and can ship at 7 or 8 weeks of age.
How do you determine if the mice responded to treatment?
Mice are added to inventory after confirming that blood glucose exceeds 250 mg/dL; this testing is typically performed the week after injections. In addition, all mice must appear overtly healthy without significant changes in body weight.
Will you consider modifying your STZ-injection protocol?
We will evaluate alternative protocols on a case-by-case basis. Using alternative protocols requires the approval from our Animal Care and Use Committee (ACUC) and will be considered pilot experiments.
Do you ship STZ-injected mice internationally?
Out of concern for the health/survival of the mice, we do not ship mice internationally. However, we can collect, fix, and ship injected mouse tissues internationally. Additionally, we can block tissues, make H&E slides, and provide pathological analysis from a board-certified mouse veterinary pathologist. Please contact email@example.com for more information.
What are the characteristics of STZ mice over time?
Our studies have shown that C57BL/6J males can remain diabetic for months after injections while maintaining body weight. We have not assessed the long term effects of shipping, but in-house shipping studies have shown that glucose levels are maintained during transit and for at least several weeks after arrival.