(Leslie Stone)
While securly holding mouse, dip end of tail into a mixture of water and crushed ice.
Hold tail in ice for several minutes to numb
Using sharp razor blade, cut off very tip of tail (do Not need a lot of tissue)
Return mouse to labeled cage (tail may bleed a little)
Put tail tip into labeled tube containing 0.1 M phosphate buffer
Transfer tail into standard X-gal solution,
Incubate overnight at 37 °C
The next day, tail tips from H253 transgenic mice will be blue