Non-Animals (e.g., cells, well plates, flasks):
These specimens are typically irradiated on Levels 3,
4, 5 using the Aluminum Specimen Shelf (“shelf
plate”). Due to the high risk of burns we do not use
level 6 or 7.
A couple of points regarding using levels and the
shelf-plate:
- To ensure relative dose uniformity; if you
are
using the shelf plate, the specimen(s)
should fit
within the circular area of the level you are irradiating at (85% dose
uniformity at outer edges of the circle). For the a specimen inside the
RAD+
reflector block, the uniformity is 98%.
- The radiation dose rate is highly dependent upon the distance from the
radiation source (x-ray tube). Therefore, for certain specimens (e.g., test
tubes, flasks, plates) you should lay items horizontally to maintain the dose
required. Do not stack plates since the higher plates will be irradiated at a
higher dose.
- The radiation dose rate is highly dependent upon the density of the
specimen. Tubes are fine but if you have your sample in an ice bucket you
may need to adjust your irradiation time.
The dose rates and corresponding irradiation times are given on a “Dose
Chart” which is posted on the front of each irradiator, as well as on our
website:
https://www.immunology.umn.edu/research-equipment-services/x-ray-irradiator .
