**2.6 Subcellular boron distribution**

In 5 min., 1 and 24 h after BSH, KUG-1 administration experimental tumors were excised, rinsed, weighed and homogenized. The cell organelles were prepared using routine techniques of differential centrifugation (De Duve, 1967).

Subcellular fractions (nuclei, mitochondria, lysosomes, cytosol) were received for further boron determination with PGNAA method.
