However, the radiometric system is more labor

intensive, requires disposal of radioactive material and

still cannot detect some Mycobacterium tuberculosis

isolates that can only be detected on agar slants. Some

laboratories prefer to use LJ slants as a backup to

Radiometric media. Considering the cost aspects and

the fact that Mycobacterium tuberculosis is largely a

problem of the third world, use of radiometric media is

still restricted and use of solid and liquid media is widely

practiced.