Help Topics

Help Topics for portal search
  1. Literature
  2. Do I need to obtain membership in PubMed Commons to access full-text articles?
  3. How can I find articles similar to the one I've located?
  4. How can I get an alert when a new article of my interest has been added to PubMed?
  5. How do I correct an error in the PubMed citation for my article?
  6. How do I determine who to contact to obtain permission for reproducing either a portion of or an entire PMC article?
  7. More...
  1. Health
  2. How do I find information on a genetic disease and how do I locate a genetics professional?
  3. How do I find out if there are any ongoing clinical trials for a specific condition and if there is an opportunity to participate in a study?
  4. How do I get advice about my disease and its treatment?
  5. What information can I find in the ClinVar database?
  6. What information will I be able to find in the Genetic Testing Registry (GTR)?
  7. More...
  1. Genomes
  2. How are genome assemblies generated and what are assembly levels?
  3. How are organisms in the NCBI Taxonomy database formally named?
  4. How do I access all sequence records for a genome assembly on the web?
  5. How do I find out if the genome for my organism of interest has been sequenced?
  6. How do I find the complete taxonomic lineage for an organism?
  7. More...
  1. Genes
  2. How can I compare expression of a gene of interest between different tissues?
  3. How can I find tissue-specific expression data for a gene of interest?
  4. How can I find variation features annotated on GenBank records?
  5. How do I find expression data for my gene of interest under various experimental conditions?
  6. How do I find specific gene expression studies?
  7. More...
  1. Proteins
  2. How are GenBank protein sequences determined?
  3. How do I find out if there is a RefSeq or UniProtKB (Swiss-Prot) sequence that is identical to my protein of interest?
  4. How do I find protein sequences that belong to a protein family?
  5. How do I obtain a curated set of proteins for my organism or taxonomic group?
  6. How do I obtain subsets of the human proteome?
  7. More...
  1. Chemicals
  2. A PubChem Compound/PubChem Substance record lists an incorrect Chemical Abstracts Registry Number (CAS RN). Can you correct it?
  3. Can I buy a chemical from NCBI?
  4. Could you correct a PubChem Substance record that displays an incorrect structure or name?
  5. What is the difference between the PubChem Substance and PubChem Compound database and which one should I search?
  1. Submit
  2. How are GenBank accession numbers assigned to my submission?
  3. How do I find the release date and/or any update date of a GenBank (Nucleotide) sequence record?
  4. I have published in a journal that does not appear in PubMed. Can I submit my manuscript to PubMed and/or PubMed Central to have it listed on your site?
  5. I have sequenced an entire genome (transcriptome). How do I submit it to GenBank?
  6. What are GenBank accession numbers and what information is embedded in them?
  7. More...
  1. Download
  2. Can I bulk-download full-text articles from PubMed Central® for my research?
  3. How can I download RefSeq data for all complete bacterial genomes?
  4. How do I convert a list of sequence accession numbers into a list of gene symbols or Gene IDs?
  5. How do I download GenBank (INSDC) genome assemblies for viruses?
  6. How do I download RefSeq genome data for viruses?
  7. More...
  1. My NCBI/Accounts
  2. Am I required to create an NCBI account?
  3. As an NIH-funded author, how do I add and maintain citations in My Bibliography?
  4. As an NIH-funded investigator, how do I associate my awards with PubMed citations?
  5. As an NIH-funded investigator, how do I monitor my compliance status using My NCBI?
  6. How do I change the email address associated with my NCBI account?
  7. More...
  1. Develop/APIs
  2. How can I download a list of IDs for all sequences from a specific organism or taxonomic group?
  3. How do I convert my list of GI numbers into the corresponding accession.version numbers?
  4. What are NCBI's guidelines for high-frequency retrievals using NCBI web services?
  5. What resources are available at NCBI for developers and other power users?
  6. Why and how should I get an API key to use the E-utilities?
  1. BLAST
  2. How can I limit standalone BLAST+ searches by organism?
  3. How many sequences can I submit for a BLAST search at one time?
  4. When I run a BLAST search, why do I get a “Process terminated by SIGXCPU” error?
  5. Why do I see only 100 sequences in my BLAST search results even though I changed Max target sequences to 500 prior to my search?
  6. Why doesn't BLAST find my sequence even though it is in GenBank?
  1. About NCBI
  2. How do I cite NCBI services and databases?
  3. How do I keep current with developments at NCBI?
  4. How do I obtain written permission to re-use NCBI materials and/or reproduce NCBI images?
  5. What are accession numbers?
  6. What are the minimum browser requirements for PubMed/NCBI?
  7. More...