BioMax TranScreen Intensifying Screen/BioMax MS Film Detection Sensitivities Table

Isotope Screen Total discharges/mm 2 required to create a
medium image (50%
net transmission)
(Not dpm)
Number of moles/mm 2 required to achieve a medium band in a
18-hour exposure
32 P BioMax TranScreen HE
Intensifying Screen
1.3 x 10 3 6.0 x 10 -20 
35 S BioMax TranScreen LE
Intensifying Screen
1.7 x 10 4  4.6 x 10 -18 
14C BioMax TranScreen LE
Intensifying Screen
1.7 x 10 4* 1.1 x 10 -13* 
45 Ca BioMax TranScreen LE
Intensifying Screen
9.1 x 10 3*  4.7 x 10 -18* 
33 P BioMax TranScreen LE
Intensifying Screen
9.1 x 10 3*  7.2 x 10 -19* 
3 H BioMax TranScreen LE
Intensifying Screen
1.6 x 10 6  2.3 x 10 -14 

* Estimated values
Above measures cited as average band densities for isotopes deposited on a white backing. Total doses of one third to four times these values are recommended to take advantage of film contrast. Note that these estimates are given as total discharges; hence, a typical small target on a Southern blot may be 100 dpm of 32 P confined to a 10 mm 2 band, yielding a perceptible image in only 100 minutes of film exposure.
The table (above) and figure (below) demonstrate the high sensitivity of the BioMax TranScreen systems by listing the minimum levels of isotope required to achieve an image (0.301 OD or 0.1 OD) for various beta emitters. The BioMax TranScreen HE was used to determine the minimum level for 32 P, while the BioMax TranScreen LE was used for 3 H, 14 C, 35 S 45 Ca, and 33 P.
The table (above) and graph demonstrate the high sensitivity of the BioMax TranScreen systems by listing the minimum levels of isotope required.

Graph of Isotope responses to the BioMax TranScreen System

TranScreen HE: 

  • Southern using 32 P - See an image after 1-hour exposure using a 500 base unique-sequence probe used at 1% efficiency.

TranScreen LE:

  • In-Situ Hybridization using 35 S - See a medium image after an 18 hour exposure using 3X104 35 S atoms per 100mm diameter area.
  • Western blot using 3 H - See a medium image after an 18 hour exposure using 10-4 cell fraction of 30kD mass, 10 µg gel load.