  Recent single molecule experiments probing the passage process of a short
single-stranded DNA (ssDNA) through a membrane channel (translocation) allow to
measure the passage time distribution. Building on a recent modelling approach
(D. K. Lubensky and D. R. Nelson, Biophys. J. 77, 1824 (1999)), which has been
demonstrated to be valid for chains of up to $\simeq 300$ nucleotides and
therefore well applies to the system we have in mind, we discuss the
consequences if the associated dynamics is not of Markov origin, but if strong
memory effects prevail during the translocation. Motivation is drawn from
recent results indicating that the distribution of translocation times is
broader than predicted by simple Markovian models based on Brownian motion.
