However,
the
results
discussed
in
this
paper,
obtained
with
DNA
of
known
molec-
ular
weight,
much
higher
than
that
considered
by
Levinthal
and
Crane,
open
the
question
again.
We
have
found
that
at
pH
12.5
the
total
unwinding
of
a
T2
DNA
molecule
requires
about
one
second.
If
we
use
the
formula
of
Levinthal
and
Crane
to
give
a
very
rough
estimation
of
the
energy
required
by
a
DNA
molecule
of
120-