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<meta name="robots" content="INDEX,FOLLOW,NOARCHIVE" /><meta name="citation_inbook_title" content="NCBI News [Internet]" /><meta name="citation_title" content="NCBI News, November 2008" /><meta name="citation_publisher" content="National Center for Biotechnology Information (US)" /><meta name="citation_date" content="2008/10/28" /><meta name="citation_author" content="Dawn Lipshultz" /><meta name="citation_author" content="Peter Cooper" /><meta name="citation_fulltext_html_url" content="https://www.ncbi.nlm.nih.gov/books/NBK2593/" /><link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" /><meta name="DC.Title" content="NCBI News, November 2008" /><meta name="DC.Type" content="Text" /><meta name="DC.Publisher" content="National Center for Biotechnology Information (US)" /><meta name="DC.Contributor" content="Dawn Lipshultz" /><meta name="DC.Contributor" content="Peter Cooper" /><meta name="DC.Date" content="2008/10/28" /><meta name="DC.Identifier" content="https://www.ncbi.nlm.nih.gov/books/NBK2593/" /><meta name="description" content="This service integrates primer designing code from the popular Primer3 1 software with a specificity check that uses a custom BLAST search. Primer-BLAST eliminates the need to design primers at another site and then perform a search with those primers using the main NCBI BLAST service to check specificity. Moreover, Primer-BLAST can design primers that amplify only a particular splice variant of a gene an important feature for PCR protocols measuring tissue specific expression. Primer-BLAST has a number of additional enhancements that make it better at picking specific primers than Primer3 and NCBI BLAST used separately." /><meta name="og:title" content="NCBI News, November 2008" /><meta name="og:type" content="book" /><meta name="og:description" content="This service integrates primer designing code from the popular Primer3 1 software with a specificity check that uses a custom BLAST search. Primer-BLAST eliminates the need to design primers at another site and then perform a search with those primers using the main NCBI BLAST service to check specificity. Moreover, Primer-BLAST can design primers that amplify only a particular splice variant of a gene an important feature for PCR protocols measuring tissue specific expression. Primer-BLAST has a number of additional enhancements that make it better at picking specific primers than Primer3 and NCBI BLAST used separately." /><meta name="og:url" content="https://www.ncbi.nlm.nih.gov/books/NBK2593/" /><meta name="og:site_name" content="NCBI Bookshelf" /><meta name="og:image" content="https://www.ncbi.nlm.nih.gov/corehtml/pmc/pmcgifs/bookshelf/thumbs/th-newsncbi-lrg.png" /><meta name="twitter:card" content="summary" /><meta name="twitter:site" content="@ncbibooks" /><meta name="bk-non-canon-loc" content="/books/n/newsncbi/nov08/" /><link rel="canonical" href="https://www.ncbi.nlm.nih.gov/books/NBK2593/" /><link rel="stylesheet" href="/corehtml/pmc/css/figpopup.css" type="text/css" media="screen" /><link rel="stylesheet" href="/corehtml/pmc/css/bookshelf/2.26/css/books.min.css" type="text/css" /><link rel="stylesheet" href="/corehtml/pmc/css/bookshelf/2.26/css/books_print.min.css" type="text/css" media="print" /><style type="text/css">p a.figpopup{display:inline !important} .bk_tt {font-family: monospace} .first-line-outdent .bk_ref {display: inline} .body-content h2, .body-content .h2 {border-bottom: 1px solid #97B0C8} .body-content h2.inline {border-bottom: none} a.page-toc-label , .jig-ncbismoothscroll a {text-decoration:none;border:0 !important} .temp-labeled-list .graphic {display:inline-block !important} .temp-labeled-list img{width:100%}</style><script type="text/javascript" src="/corehtml/pmc/js/jquery.hoverIntent.min.js"> </script><script type="text/javascript" src="/corehtml/pmc/js/common.min.js?_=3.18"> </script><script type="text/javascript" src="/corehtml/pmc/js/large-obj-scrollbars.min.js"> </script><script type="text/javascript">window.name="mainwindow";</script><script type="text/javascript" src="/corehtml/pmc/js/bookshelf/2.26/book-toc.min.js"> </script><script type="text/javascript" src="/corehtml/pmc/js/bookshelf/2.26/books.min.js"> </script><meta name="book-collection" content="NONE" />
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<div class="pre-content"><div><div class="bk_prnt"><p class="small">NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.</p><p>NCBI News [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 1991-2012. </p></div><div class="iconblock clearfix whole_rhythm no_top_margin bk_noprnt"><a class="img_link icnblk_img" title="Table of Contents Page" href="/books/n/newsncbi/"><img class="source-thumb" src="/corehtml/pmc/pmcgifs/bookshelf/thumbs/th-newsncbi-lrg.png" alt="Cover of NCBI News" height="100px" width="80px" /></a><div class="icnblk_cntnt eight_col"><h2>NCBI News [Internet].</h2><a data-jig="ncbitoggler" href="#__NBK2593_dtls__">Show details</a><div style="display:none" class="ui-widget" id="__NBK2593_dtls__"><div>Bethesda (MD): <a href="https://www.ncbi.nlm.nih.gov/news" ref="pagearea=page-banner&amp;targetsite=external&amp;targetcat=link&amp;targettype=publisher">National Center for Biotechnology Information (US)</a>; 1991-2012.</div></div><div class="half_rhythm"><ul class="inline_list"><li style="margin-right:1em"><a class="bk_cntns" href="/books/n/newsncbi/">Index of Issues</a></li></ul></div><div class="bk_noprnt"><form method="get" action="/books/n/newsncbi/" id="bk_srch"><div class="bk_search"><label for="bk_term" class="offscreen_noflow">Search term</label><input type="text" title="Search this book" id="bk_term" name="term" value="" data-jig="ncbiclearbutton" /> <input type="submit" class="jig-ncbibutton" value="Search this book" submit="false" style="padding: 0.1em 0.4em;" /></div></form></div></div><div class="icnblk_cntnt two_col"><div class="pagination bk_noprnt"><a class="active page_link prev" href="/books/n/newsncbi/dec08/" title="Previous page in this title">&lt; Prev</a><a class="active page_link next" href="/books/n/newsncbi/aug08/" title="Next page in this title">Next &gt;</a></div></div></div></div></div>
<div class="main-content lit-style" itemscope="itemscope" itemtype="http://schema.org/CreativeWork"><div class="meta-content fm-sec"><h1 id="_NBK2593_"><span class="title" itemprop="name">NCBI News, November 2008</span></h1><p class="contrib-group"><span itemprop="author">Dawn Lipshultz</span>, M.S. and <span itemprop="author">Peter Cooper</span>, Ph.D.</p><a data-jig="ncbitoggler" href="#__NBK2593_ai__" style="border:0;text-decoration:none">Author Information and Affiliations</a><div style="display:none" class="ui-widget" id="__NBK2593_ai__"><div class="contrib half_rhythm"><span itemprop="author">Dawn Lipshultz</span>, M.S.<div class="affiliation small">NCBI<div><span class="email-label">Email: </span><a href="mailto:dev@null" data-email="vog.hin.mln.ibcn@tluhspil" class="oemail">vog.hin.mln.ibcn@tluhspil</a></div></div></div><div class="contrib half_rhythm"><span itemprop="author">Peter Cooper</span>, Ph.D.<div class="affiliation small">NCBI<div><span class="email-label">Email: </span><a href="mailto:dev@null" data-email="vog.hin.mln.ibcn@repooc" class="oemail">vog.hin.mln.ibcn@repooc</a></div></div></div></div><p class="small">Created: <span itemprop="datePublished">October 15, 2008</span>; Last Update: <span itemprop="dateModified">October 28, 2008</span>.</p><p><em>Estimated reading time: 6 minutes</em></p></div><div class="jig-ncbiinpagenav body-content whole_rhythm" data-jigconfig="allHeadingLevels: ['h2'],smoothScroll: false" itemprop="text"><div id="nov08.Featured_Resource_Pr"><h2 id="_nov08_Featured_Resource_Pr_">Featured Resource: Primer-BLAST&#x02014;NCBI&#x02019;s Primer Designer and
Specificity Checker</h2><p>NCBI now offers Primer-BLAST, a Web service for designing target specific oligonucleotide
primers for use in polymerase chain reaction (PCR) protocols. Primer-BLAST may be accessed
from the NCBI BLAST Homepage or through the direct URL:</p><p>
<a href="/tools/primer-blast" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">http://www.ncbi.nlm.nih.gov/tools/primer-blast/</a>
</p><p>This service integrates primer designing code from the popular Primer3<a href="#nov08.Reference">
<sup>1</sup>
</a> software with a specificity check that uses a custom BLAST search. Primer-BLAST
eliminates the need to design primers at another site and then perform a search with those
primers using the main NCBI BLAST service to check specificity. Moreover, Primer-BLAST can
design primers that amplify only a particular splice variant of a gene &#x02013; an
important feature for PCR protocols measuring tissue specific expression. Primer-BLAST has a
number of additional enhancements that make it better at picking specific primers than
Primer3 and NCBI BLAST used separately.</p><div id="nov08.PrimerBLAST_Input"><h3>Primer-BLAST Input</h3><p>The Primer-BLAST interface contains elements of both the Primer3 tool and the NCBI BLAST
Web service. The submission form is divided into three sections with commonly adjusted
settings relevant to the <b>target template</b>, <b>the primers,</b> and the
background <b>specificity check</b>. As with other BLAST services, the more
specialized options are available under an expandable section at the bottom of the
submission form, called &#x0201c;Advanced parameters&#x0201d; in Primer-BLAST. </p><div id="nov08.Template"><h4>Template</h4><p>The target template sequence or accession number to be analyzed is placed in the large
text area in the <b>PCR Template</b> section of the form. Specific binding regions
on the template may be specified using the range boxes. With just the target template,
Primer-BLAST will design primer pairs that are specific to the target template and
unique in the target database. </p></div><div id="nov08.Primers"><h4>Primers</h4><p>One or both primers may be supplied in the <b>Primer Parameters</b> section. The
most important and commonly modified primer-specific parameters such as desired product
size, Tm ranges and Tm difference may be modified here as well. Primers may accompany a
template, but may also be used without a template. With only a primer pair, Primer-BLAST
identifies potential templates in the target database. In this case, the results are
more precise than a specificity check with ordinary BLAST and have additional PCR
condition parameters such as melting temperature (Tm) provided in the results. </p></div><div id="nov08.Specificity"><h4>Specificity</h4><p>Parameters that may be adjusted in the <b>Specificity Checking </b>section of the
form affect the nature of the background database and the level of stringency for
avoiding nonspecific matches. The database specificity check does not simply find BLAST
matches but includes adjustable mismatch cutoffs that focus on the 3&#x02032; end of
the binding site to more effectively avoid mispriming. The most informative results are
obtained by selecting the target database and organism that best match the template
sequence source. The organism selection is managed by typing the name of the organism of
interest in the &#x0201c;Organism&#x0201d; box. An auto-complete feature will
find the closest match in the NCBI taxonomy database. </p><p>Four BLAST nucleotide databases are available for searching: RefSeq mRNA, Genome
(selected reference assemblies), Genome (all chromosomes), and nr (the standard
non-redundant database). The first two databases will give the most precise results as
these are the best annotated and analyzed sets of sequences. In particular, if an NCBI
mRNA Reference Sequence is used as a template with the RefSeq mRNA database,
Primer-BLAST will design primers specific to the single splice variant represented by
the reference sequence. The well characterized genome sequences of human, chimpanzee,
mouse, rat, cow, dog, chicken, zebrafish, fruit fly, honeybee,
<i>Arabidopsis</i>, and rice are available as the selected reference
assemblies. These selected reference assemblies will produce results that are less
redundant and easier to interpret when using genomic templates from these organisms. The
remaining Genome database (all chromosomes) contains all chromosome Reference Sequences
(NC_ accessions) including the selected reference assemblies, as well as their
alternative assemblies, and chromosome records for other organisms, most notably
microbial genome sequences. Finally, the nr database is available for the widest
coverage of organisms.</p></div><div id="nov08.Advanced_Parameters"><h4>Advanced Parameters</h4><p>The <b>Advanced Parameters</b> section contains numerous adjustable settings
affecting primer binding and efficacy from the Primer3 program. Two additional features
that are only available in Primer-BLAST are options to avoid making primers that match
repetitive or regions with biased base composition (low complexity regions) and an
option to avoid regions that contain reported nucleotide polymorphisms (SNPs) from
NCBI&#x02019;s SNP database. As with Primer3, Primer-BLAST also has an option to
design an internal hybridization probe for each product that can be used in various
product detection assays.</p></div></div><div id="nov08.Example"><h3>Example</h3><p>Using Primer-BLAST to design primers to distinguish the two transcripts of the human
uracil-DNA glycosylase genes (UNG, GeneID: 7374) demonstrates the utility and precision of
Primer BLAST (<a class="figpopup" href="/books/NBK2593/figure/nov08.nov08_fig1/?report=objectonly" target="object" rid-figpopup="fignov08nov08fig1" rid-ob="figobnov08nov08fig1">Figure 1</a>). The UNG products code for enzymes
involved in removing misincorpated uracil during DNA replication. The longer UNG1
transcript (<a href="/nuccore/1677530039" class="bk_tag" ref="pagearea=body&amp;targetsite=entrez&amp;targetcat=link&amp;targettype=nuccore">NM_003362</a> ) codes for a mitochondrial enzyme while the shorter UNG2 transcript
(<a href="/nuccore/1677498868" class="bk_tag" ref="pagearea=body&amp;targetsite=entrez&amp;targetcat=link&amp;targettype=nuccore">NM_080911</a>) that lacks the portion coding for the mitochondrial targeting sequence
apparently functions in the nuclear genome of replicating cells. The top panel of Figure 1
shows the Primer-BLAST results that are specific to the UNG2 splice variant. In this case
the NCBI reference sequence was used as a template with RefSeq mRNA database limited to
human. By default the service designs only UNG2 specific primers with the reference
sequence as the template. These conditions may be relaxed by checking the option for
&#x0201c;Allow primer to amplify mRNA splice variants.&#x0201d; The bottom panel
of Figure 1 shows that under these conditions new primers are found that will amplify both
transcripts from the UNG gene. Expanding the database coverage provides a means for
checking primers in additional species. The results using the nr database predict that
many of the primer pairs designed against the human UNG transcripts should also amplify
transcripts from other primate species (not shown). </p><div class="iconblock whole_rhythm clearfix ten_col fig" id="fignov08nov08fig1" co-legend-rid="figlgndnov08nov08fig1"><a href="/books/NBK2593/figure/nov08.nov08_fig1/?report=objectonly" target="object" title="Figure 1" class="img_link icnblk_img figpopup" rid-figpopup="fignov08nov08fig1" rid-ob="figobnov08nov08fig1"><img class="small-thumb" src="/books/NBK2593/bin/nov08.G1.gif" src-large="/books/NBK2593/bin/nov08.G1.jpg" alt="Figure 1. Primer-BLAST results for UNG transcript variant 2." /></a><div class="icnblk_cntnt" id="figlgndnov08nov08fig1"><h4 id="nov08.nov08_fig1"><a href="/books/NBK2593/figure/nov08.nov08_fig1/?report=objectonly" target="object" rid-ob="figobnov08nov08fig1">Figure 1</a></h4><p class="float-caption no_bottom_margin">Primer-BLAST results for UNG transcript variant 2. The NCBI
Reference sequence NM_080911 was used as a template. <i>Top panel:</i> Primers
specific to the single splice variant are reported by default with the mRNA RefSeq
database limited to human sequences. <a href="/books/NBK2593/figure/nov08.nov08_fig1/?report=objectonly" target="object" rid-ob="figobnov08nov08fig1">(more...)</a></p></div></div></div><div id="nov08.Summary"><h3>Summary</h3><p>Primer-BLAST provides a new more powerful and more comprehensive primer design tool by
combining oligonucleotide primer design with specific genome and transcriptome level
searches, and will save time and money by eliminating some of the trial and error of PCR
primer design.</p></div><div id="nov08.Reference"><h3>Reference</h3><ol><li><div class="bk_ref" id="nov08.MN.1">1. Steve Rozen and Helen J. Skaletsky (2000)
Primer3 on the WWW for general users and for biologist programmers. <strong>In:</strong>
Krawetz S, Misener S (eds) <em>Bioinformatics Methods and Protocols: Methods in
Molecular Biology.</em> Humana Press, Totowa, NJ, pp 365-386 [<a href="https://pubmed.ncbi.nlm.nih.gov/10547847" ref="pagearea=cite-ref&amp;targetsite=entrez&amp;targetcat=link&amp;targettype=pubmed">PubMed<span class="bk_prnt">: 10547847</span></a>]</div></li></ol></div></div><div id="nov08.New_Databases_and_To"><h2 id="_nov08_New_Databases_and_To_">New Databases and Tools</h2><div id="nov08.BLAST_2_Sequences"><h3>BLAST 2 Sequences</h3><p>The NCBI BLAST web pages have a new option to align a query against a set of target
sequences, rather than a BLAST database. This option allows you to align your query to one
or more subject sequences and still use the standard BLAST web interface to optimize your
search and change algorithm parameters. Each search is assigned a "Request ID" (RID) and
is also listed under the "Recent Results" tab that you can access from the BLAST home
page. The results are formatted as a standard BLAST report, except a "Dot Matrix view" (a
"dot-plot" like graphic of the alignments) is available in the new report design if only
one subject sequence was searched. Links to BLAST web pages can be found at:
blast.ncbi.nlm.nih.gov/BLAST.cgi Step-by-step instructions can be found at: <a href="http://blast.ncbi.nlm.nih.gov/docs/align_seqs.pdf" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">blast.ncbi.nlm.nih.gov/docs/align_seqs.pdf</a></p></div><div id="nov08.My_NCBI"><h3>My NCBI</h3><p>My NCBI version 2.0 was released in September with new features and updated functions.
New features include: account and username options; navigation, preferences, and filter
improvements; My Saved Searches tool; and My Collections tool. Another new feature, My
Bibliography, allows authors to search and collect citations for their publications. For a
full description of new and improved features, please see the <i>NLM Technical
Bulletin</i> article at: <a href="http://www.nlm.nih.gov/pubs/techbull/so08/so08_myncbi_redesign.html" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">www.nlm.nih.gov/pubs/techbull/so08/so08_myncbi_redesign.html</a> . My NCBI is
located at: <a href="/sites/myncbi" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">www.ncbi.nlm.nih.gov/sites/myncbi/</a></p></div><div id="nov08.BarSTool"><h3>BarSTool</h3><p>The Barcode of Life project is one in which DNA barcode sequences are being collected
from vouchered specimens of all biological species. The idea is to make it easier to
identify biological specimens via a short gene sequence from a standardized position in
the genome. NCBI has created a submission tool, Barcode Submission Tool (BarSTool), to
submit barcode sequences to GenBank. For more information about BarSTool or the Barcode of
Life project see: <a href="http:///Local%20Settings/Temporary%20Internet%20Files/OLK80/www.ncbi.nlm.nih.gov/Genbank/barcode.html" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">www.ncbi.nlm.nih.gov/Genbank/barcode.html</a>.</p></div><div id="nov08.Bookshelf"><h3>Bookshelf</h3><p>The Bookshelf has added two new books entitled: <i>Hepatitis C Viruses: Genomes and
Molecular Biology</i> and <i>NCBI News</i>. Books can be found at:
<a href="/sites/entrez?db=Books" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">www.ncbi.nlm.nih.gov/sites/entrez?db=Books</a>.</p></div><div id="nov08.Microbial_Genomes"><h3>Microbial Genomes</h3><p>Thirty-two finished microbial genomes were released (August 15-October 10). The original
sequence data files submitted to GenBank/EMBL/DDBJ can be found at: <a href="ftp://ftp.ncbi.nih.gov/genbank/genomes/Bacteria" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=ftp">ftp://ftp.ncbi.nih.gov/genbank/genomes/Bacteria/</a>. The RefSeq provisional
versions of these genomes are available via FTP at: <a href="ftp://ftp.ncbi.nih.gov/genomes/Bacteria" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=ftp">ftp://ftp.ncbi.nih.gov/genomes/Bacteria/</a>.</p></div></div><div id="nov08.GenBank_News"><h2 id="_nov08_GenBank_News_">GenBank News</h2><p>GenBank release 167.0 is available via web and FTP that includes information as of August
19, 2008.</p></div><div id="nov08.Updates_and_Enhancem"><h2 id="_nov08_Updates_and_Enhancem_">Updates and Enhancements</h2><div id="nov08.Discovery_PubMed_Pag"><h3>Discovery PubMed Pages</h3><p>PubMed Summary results pages have begun showing related information from other resources
on the right side of the page. Drug Sensor, an NCBI tool that detects drug names in a
search, was released in August. As of September, additional resources will be shown to a
percentage of users to aid in the discovery process.</p></div><div id="nov08.RefSeq"><h3>RefSeq</h3><p>RefSeq Release 31 is available via web and FTP. This full release incorporates genomic,
transcript, and protein data available as of August 30, 2008 and includes 9,145,702
records, 5,859,648 &#x000a0;proteins, and sequences from 5,513 different organisms. </p><p>The RefSeq website is: <a href="/RefSeq" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">www.ncbi.nlm.nih.gov/RefSeq/</a>.</p></div><div id="nov08.Genome_Assembly"><h3>Genome Assembly</h3><p>Genome annotation for <i>Ciona intestinalis</i> build 1.1 and
<i>Arabidopsis thaliana</i> build 8.1 were released in September. For more
annotation updates and links to Genome Resource pages see: <a href="/Genomes" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">www.ncbi.nlm.nih.gov/Genomes/</a>.</p></div></div><div id="nov08.Announce_Lists_and_R"><h2 id="_nov08_Announce_Lists_and_R_">Announce Lists and RSS Feeds</h2><p>Fifteen topic-specific mailing lists are described on the Announcement List summary page.
Announce lists provide email announcements about changes and updates to NCBI resources.
<a href="/Sitemap/Summary/email_lists.html" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">http://www.ncbi.nlm.nih.gov/Sitemap/Summary/email_lists.html</a></p><p>Seven RSS feeds are now available from NCBI including news on PubMed, PubMed Central, NCBI
Bookshelf, LinkOut, HomoloGene, UniGene, and NCBI Announce. <a href="/feed" ref="pagearea=body&amp;targetsite=external&amp;targetcat=link&amp;targettype=uri">http://www.ncbi.nlm.nih.gov/feed/</a></p><p>Comments and questions about NCBI resources may be sent to NCBI at:
<a href="mailto:dev@null" data-email="vog.hin.mln.ibcn@ofni" class="oemail">vog.hin.mln.ibcn@ofni</a>, or by calling 301-496-2475 between the hours of 8:30
a.m. and 5:30 p.m. EST, Monday through Friday.</p></div><div id="bk_toc_contnr"></div></div></div>
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