6 research outputs found
Improved Lower Bounds for Constant GC-Content DNA Codes
The design of large libraries of oligonucleotides having constant GC-content
and satisfying Hamming distance constraints between oligonucleotides and their
Watson-Crick complements is important in reducing hybridization errors in DNA
computing, DNA microarray technologies, and molecular bar coding. Various
techniques have been studied for the construction of such oligonucleotide
libraries, ranging from algorithmic constructions via stochastic local search
to theoretical constructions via coding theory. We introduce a new stochastic
local search method which yields improvements up to more than one third of the
benchmark lower bounds of Gaborit and King (2005) for n-mer oligonucleotide
libraries when n <= 14. We also found several optimal libraries by computing
maximum cliques on certain graphs.Comment: 4 page
On Critical Relative Distance of DNA Codes for Additive Stem Similarity
We consider DNA codes based on the nearest-neighbor (stem) similarity model
which adequately reflects the "hybridization potential" of two DNA sequences.
Our aim is to present a survey of bounds on the rate of DNA codes with respect
to a thermodynamically motivated similarity measure called an additive stem
similarity. These results yield a method to analyze and compare known samples
of the nearest neighbor "thermodynamic weights" associated to stacked pairs
that occurred in DNA secondary structures.Comment: 5 or 6 pages (compiler-dependable), 0 figures, submitted to 2010 IEEE
International Symposium on Information Theory (ISIT 2010), uses IEEEtran.cl
Random Coding Bounds for DNA Codes Based on Fibonacci Ensembles of DNA Sequences
We consider DNA codes based on the concept of a weighted 2-stem similarity measure which reflects the ”hybridization potential” of two DNA sequences. A random coding bound on the rate of DNA codes with respect to a thermodynamic motivated similarity measure is proved. Ensembles of DNA strands whose sequence composition is restricted in a manner similar to the restrictions in binary Fibonacci sequences are introduced to obtain the bound
Thermodynamically Stable DNA Code Design using a Similarity Significance Model
DNA code design aims to generate a set of DNA sequences (codewords) with
minimum likelihood of undesired hybridizations among sequences and their
reverse-complement (RC) pairs (cross-hybridization). Inspired by the distinct
hybridization affinities (or stabilities) of perfect double helix constructed
by individual single-stranded DNA (ssDNA) and its RC pair, we propose a novel
similarity significance (SS) model to measure the similarity between DNA
sequences. Particularly, instead of directly measuring the similarity of two
sequences by any metric/approach, the proposed SS works in a way to evaluate
how more likely will the undesirable hybridizations occur over the desirable
hybridizations in the presence of the two measured sequences and their RC
pairs. With this SS model, we construct thermodynamically stable DNA codes
subject to several combinatorial constraints using a sorting-based algorithm.
The proposed scheme results in DNA codes with larger code sizes and wider free
energy gaps (hence better cross-hybridization performance) compared to the
existing methods.Comment: To appear in ISIT 202