MultiPLX: automatic grouping and evaluation of PCR primers

SUMMARY: MultiPLX is a new program for automatic grouping of PCR primers. It can use many different parameters to estimate the compatibility of primers, such as primer-primer interactions, primer-product interactions, difference in melting temperatures, difference in product length and the risk of generating alternative products from the template. A unique feature of the MultiPLX is the ability to perform automatic grouping of large number (thousands) of primer pairs. AVAILABILITY: Binaries for Windows, Linux and Solaris are available from http://bioinfo.ebc.ee/download/. A graphical version with limited capabilities can be used through a web interface at http://bioinfo.ebc.ee/multiplx/. The source code of the program is available on request for academic users. CONTACT: maido.remm@ut.ee.     

EasyExonPrimer

EasyExonPrimer is a web-based software that automates the design of PCR primers to amplify exon sequences from genomic DNA. EasyExonPrimer is written in Perl and uses Primer3 to design PCR primers based on the genome builds and annotation databases available at the University of California, Santa Cruz (UCSC) Genome Browser database (http://genome.ucsc.edu/). It masks repeats and known single nucleotide polymorphism (SNP) sites in the genome and designs standardised primers using optimised conditions. Users can input genes by RefSeq mRNA ID, gene name or keyword. The primer design is optimised for large-scale resequencing of exons. For exons larger than 1 kb, the user has the option of breaking the exon sequence down into overlapping smaller fragments. All primer pairs are then verified using the In-Silico PCR software to test for uniqueness in the genome. We have designed >1000 pairs of primers for 90 genes; 95% of the primer pairs successfully amplified exon sequences under standard PCR conditions without requiring further optimisation. AVAILABILITY: EasyExonPrimer is available from http://129.43.22.27/~primer/. The source code is also available upon request. CONTACT: Xiaolin Wu (forestwu@mail.nih.gov).     

URPD: A Specific Product Primer Design Tool

ABSTRACT: BACKGROUND: Polymerase chain reaction (PCR) plays an important role in molecular biology. Primer design fundamentally determines its results. Here, we present a currently available software for a rather straight-forward way of visualizing the primer design process for infrequent users. RESULTS: URPD (yoUR Primer Design), a web-based specific product primer design tool, combines the NCBI Reference Sequences (RefSeq), UCSC In-Silico PCR, memetic algorithm (MA) and genetic algorithm (GA) primer design methods to obtain specific primer sets. A friendly user interface is accomplished by built-in parameter settings. The incorporated smooth pipeline operations effectively guide both occasional and advanced users. URPD contains an automated process, which produces feasible primer pairs that satisfy the specific needs of the experimental design with practical PCR amplifications. Visual virtual gel electrophoresis and in silico PCR provide a simulated PCR environment. The comparison of Practical gel electrophoresis comparison to virtual gel electrophoresis facilitates and verifies the PCR experiment. Wet-laboratory validation proved that the system provides feasible primers. CONCLUSIONS: URPD is a user-friendly tool that provides specific primer design results. The pipeline design path makes it easy to operate for beginners. URPD also provides a high throughput primer design function. Moreover, the advanced parameter settings assist sophisticated researchers in performing experiential PCR. Several novel functions, such as a nucleotide accession number template sequence input, local and global specificity estimation, primer pair redesign, user-interactive sequence scale selection, and virtual and practical PCR gel electrophoresis discrepancies have been developed and integrated into URPD. The URPD program is implemented in JAVA and freely available at http://bio.kuas.edu.tw/urpd/.     

Primer3--new capabilities and interfaces

Polymerase chain reaction (PCR) is a basic molecular biology technique with a multiplicity of uses, including deoxyribonucleic acid cloning and sequencing, functional analysis of genes, diagnosis of diseases, genotyping and discovery of genetic variants. Reliable primer design is crucial for successful PCR, and for over a decade, the open-source Primer3 software has been widely used for primer design, often in high-throughput genomics applications. It has also been incorporated into numerous publicly available software packages and web services. During this period, we have greatly expanded Primer3's functionality. In this article, we describe Primer3's current capabilities, emphasizing recent improvements. The most notable enhancements incorporate more accurate thermodynamic models in the primer design process, both to improve melting temperature prediction and to reduce the likelihood that primers will form hairpins or dimers. Additional enhancements include more precise control of primer placement-a change motivated partly by opportunities to use whole-genome sequences to improve primer specificity. We also added features to increase ease of use, including the ability to save and re-use parameter settings and the ability to require that individual primers not be used in more than one primer pair. We have made the core code more modular and provided cleaner programming interfaces to further ease integration with other software. These improvements position Primer3 for continued use with genome-scale data in the decade ahead.     

Primer Design Assistant (PDA): A web-based primer design tool

Primer Design Assistant (PDA) is a web interface primer design service combined with thermodynamic theory to evaluate the fitness of primers. It runs in a Linux-Apache-MySQL-PHP structure on a PC equipped with dual CPU (Intel Pentium III 1.4 GHz) and 512 Mb of RAM. A succinct user interface of PDA is accomplished by built-in parameters setting. Advanced options on 5' GC content, 3' GC content, dimer check and hairpin check are available. The option of covered region constrains the PCR product to cover a user-defined segment. PDA accepts single sequence query or multiple ones in FASTA format. It produces optimal and homogenous primer pairs that meet the need in experimental design with large-scaled PCR amplifications. Considering the system loading, the size of a submitted sequence is limited to 10 kb and the total sequence number in a query is limited to 20. The authors may be contacted regarding other requirements for primer design. The web application can be found at http://dbb.nhri.org.tw/primer/.     

A thermodynamic approach to PCR primer design

We developed a primer design method, Pythia, in which state of the art DNA binding affinity computations are directly integrated into the primer design process. We use chemical reaction equilibrium analysis to integrate multiple binding energy calculations into a conservative measure of polymerase chain reaction (PCR) efficiency, and a precomputed index on genomic sequences to evaluate primer specificity. We show that Pythia can design primers with success rates comparable with those of current methods, but yields much higher coverage in difficult genomic regions. For example, in RepeatMasked sequences in the human genome, Pythia achieved a median coverage of 89% as compared with a median coverage of 51% for Primer3. For parameter settings yielding sensitivities of 81%, our method has a recall of 97%, compared with the Primer3 recall of 48%. Because our primer design approach is based on the chemistry of DNA interactions, it has fewer and more physically meaningful parameters than current methods, and is therefore easier to adjust to specific experimental requirements. Our software is freely available at http://pythia.sourceforge.net.     

Efficient primer design algorithms

MOTIVATION: Primer design involves various parameters such as string-based alignment scores, melting temperature, primer length and GC content. This entails a design approach from multicriteria decision making. Values of some of the criteria are easy to compute while others require intense calculations. RESULTS: The reference point method was found to be tractable for trading-off between deviations from ideal values of all the criteria. Some criteria computations are based on dynamic programs with value iteration whose run time can be bounded by a low-degree polynomial. For designing standard PCR primers, the scheme offers in a relative gain in computing speed of up to 50: 1 over ad-hoc computational methods. Single PCR primer pairs have been used as model systems in order to simplify the quantization of the computational acceleration factors. The program has been structured so as to facilitate the analysis of large numbers of primer pairs with minor modifications. The scheme significantly increases primer design throughput which in turn facilitates the use of oligonucleotides in a wide range of applications including: multiplex PCR and other nucleic acid-based amplification systems, as well as in zip code targeting, oligonucleotide microarrays and nucleic acid-based nanoengineering.     

HMMGEP: clustering gene expression data using hidden Markov models

SUMMARY: The package HMMGEP performs cluster analysis on gene expression data using hidden Markov models. AVAILABILITY: HMMGEP, including the source code, documentation and sample data files, is available at http://www.bioinfo.tsinghua.edu.cn:8080/~rich/hmmgep_download/index.html.     

PCR引物特异性核查系统(PSC)的构建与应用

聚合酶链式反应(PCR)虽已广泛用于分子生物学研究中,然而PCR实验中的非特异性产物问题将直接影响PCR的效率,在多重PCR实验中更是如此。为了最大限度地降低非特异性产物的出现率,同时避免用户频繁使用Blast比对检查非特异性,我们开发了基于NCBI-Blast的引物评估和模板DNA特异性结合能力评估的核查系统PSC(Primer Specificity Checking,http://biocompute.bmi.ac.cn/PSC),并基于虚拟PCR实验确定了用于引物质量核查计算的多种参数,能够在线提供多个物种的引物特异性核查结果。该系统可以有效地对引物序列可能产生的所有非特异性扩增进行预测,有助于实验前引物优化或者对非特异扩增结果进行解释,最终达到提高PCR效率的目的。     

ROCK: a spreadsheet-based program for the generation and analysis of random oligonucleotide primers used in PCR.

Oligonucleotide primers used to amplify target DNA regions via PCR should meet certain design criteria to maximize the potential for efficient priming. The Random Oligonucleotide Construction Kit (ROCK), a spreadsheet-based program that runs under Microsoft Excel 97 or later version for Microsoft Windows, was developed to facilitate the design of efficient random oligonucleotide primers. Primer sequences are generated that meet user-defined criteria with regard to G + C content, size of a 3' GC clamp, maximum intramolecular/intermolecular complementation potential, and maximum intersequence similarity. The user can analyze the intramolecular/intermolecular complementation potential of program-generated primer sequences or of sequences entered manually. The latter may contain any of the standard nucleotide symbols, including ambiguous bases. Primer sequence length, GC%, individual base composition, molecular weight, approximate melting temperature, and mass/volume/concentration relationships can be determined for any sequence generated by ROCK or entered manually.     

Primer Prim'r: A web based server for automated primer design

The Northeast Structural Genomics Consortium (NESG) is one of nine NIH-funded pilot projects created to develop technologies needed for structural studies of proteins on a genome-wide scale. One of the most challenging aspects of this emerging field is the production of protein samples amenable to structural determination. To do this efficiently, all steps in the protein production pipeline must be automated. Here we describe the Primer program (linked from http://www-nmr.cabm.rutgers.edu/bioinformatics, www-nmr.cabm.rutgers.edu/bioinformatics, a web-based primer design program freely available to the scientific community, which was created to automate this time consuming and laborious task. This program has the ability to simultaneously calculate plasmid specific primer sets for multiple open reading frame (ORF) targets, including 96-well and greater formats. Primer includes a library of commonly used plasmid systems and possesses the ability to upload user-defined plasmid systems. In addition to calculating gene-specific annealing regions for each target, the program also adds appropriate restriction endonuclease recognition or viral recombination sites while preserving a reading frame with plasmid based fusions. Primer has several useful features such as sorting calculated primer sets by target size, facilitating interpretation of PCR amplifications by agarose gel electrophoresis, as well as supplying the molecular biologist with many important characteristics of each target such as the expected size of the PCR amplified DNA fragment and internal restriction sites. The NESG has cloned over 1500 genes using oligonucleotide primers designed by Primer.     

Human Gene-Centric Databases at the Weizmann Institute of Science: GeneCards,UDB, CroW 21 and HORDE

Recent enhancements and current research in the GeneCards (GC) (http://bioinfo.weizmann.ac.il/cards/) project are described, including the addition of gene expression profiles and integrated gene locations. Also highlighted are the contributions of specialized associated human gene-centric databases developed at the Weizmann Institute. These include the Unified Database (UDB) (http://bioinfo.weizmann.ac.il/udb) for human genome mapping, the human Chromosome 21 database at the Weizmann Insti-tute (CroW 21) (http://bioinfo.weizmann.ac.il/crow21), and the Human Olfactory Receptor Data Explora-torium (HORDE) (http://bioinfo.weizmann.ac.il/HORDE). The synergistic relationships amongst these efforts have positively impacted the quality, quantity and usefulness of the GeneCards gene compendium.     

MEDUSA: large scale automatic selection and visual assessment of PCR primer pairs.

MEDUSA is a tool for automatic selection and visual assessment of PCR primer pairs, developed to assist large scale gene expression analysis projects. The system allows specification of constraints of the location and distances between the primers in a pair. For instance, primers in coding, non-coding, exon/intron-spanning regions might be selected. Medusa applies these constraints as a filter to primers predicted by three external programs, and displays the resulting primer pairs graphically in the Blixem (Sonnhammer and Durbin, COMPUT: Appl. Biosci. 10, 301-307, 1994; http://www.cgr.ki.se/cgr/groups/sonnhammer/Blixem.html) viewer. AVAILABILITY: The MEDUSA web server is available at http://www.cgr.ki.se/cgr/MEDUSA. The source code and user information are available at ftp://ftp.cgr.ki.se/pub/prog/medusa.     

RTPrimerDB: the real-time PCR primer and probe database

The real-time polymerase chain reaction (PCR) methodology has become increasingly popular for nucleic acids detection and/or quantification. As primer/probe design and experimental evaluation is time-consuming, we developed a public database application for the storage and retrieval of validated real-time PCR primer and probe sequence records. The integrity and accuracy of the data are maintained by linking to and querying other reference databases. RTPrimerDB provides free public access through the Web to perform queries and submit user based information. Primer/probe records can be searched for by official gene symbol, nucleotide sequence, type of application, detection chemistry, LocusLink or Single Nucleotide Polymorphism (SNP) identifier, and submitter's name. Each record is directly linked to LocusLink, dbSNP and/or PubMed to retrieve additional information on the gene/SNP for which the primers/probes are designed. Currently, the database contains primer/probe records for human, mouse, rat, fruit fly and zebrafish, and all current detection chemistries such as intercalating dyes (SYBR Green I), hydrolysis probes (Taqman), adjacent hybridizations probes and molecular beacons. Real-time PCR primer/probe records are available at http://www.realtimeprimerdatabase.ht.st.     

SNPbox: a modular software package for large-scale primer design

SUMMARY: We developed a modular software package SNPbox that automates and standardizes the generation of PCR primers and is used in the strategy for constructing single nucleotide polymorphisms (SNPs) maps. In this strategy, the focus of primer design can be either on the validation of annotated public SNPs or on the SNP discovery in exon regions or extended genomic regions, both by resequencing. SNPbox relies on Primer3 for the primer design and combines this program with other publicly available software tools such as BLAST, Spidey and RepeatMasker, and newly developed algorithms. Primer conditions were chosen such that PCR amplifications are uniform for each PCR amplicon facilitating the use of high-throughput genetic platforms. SNPbox can also be used for the design of primer sets for mutation analysis, STR marker genotyping and microarray oligo design. Of the 2500 primer sets designed by SNPbox, 95% successfully amplified genomic DNA under uniform PCR conditions. AVAILABILITY: The software is available from the authors upon request. SUPPLEMENTARY INFORMATION: SNPbox_supplement.     

DePIE: Designing Primers for Protein Interaction Experiments

Several primer prediction and analysis programs have been developed for diverse applications. However, none of these existing programs can be directly used for the design of primers in protein interaction experiments, since proteins may have transmembrane domains (TMDs) and/or a signal peptide that must be excluded from experiments. Furthermore, it is frequently the case that a short restriction sequences must be added to each primer in order to clone PCR products into a given destination vectors for expression. DePIE, a web-based primer design tool, was developed to address these deficiencies. The program takes as input NCBI protein accession numbers and returns primer information including nucleotide sequences, thermodynamic melting temperature of the nucleotide sequences and the target positions. DePIE is implemented in JAVA, PERL and PHP and has proven to be very efficient in designing primers for our interaction experiments. DePIE services can be accessed at the web site: http://biocore.unl.edu/primer/primerPI.html.