both micrococcal nuclease and dnase i digestion indicate that , unlike core particles , accessible sites occur in the centre of the particle and it is concluded that the ( h3/h4 ) 4-125-bp-dna particle is not a 'pseudo-core particle ' in which the 'extra ' h3 and h4 replace h2a and h2b .
C1518457
core particle
C0086411
h2b