Retrieve sequence records that were added or modified between two dates

If a researcher is particularly interested in the sequences associated with a specific gene or topic, they might do a periodic search to find out what new data have been added since the last time they searched. If the researcher does not want to see previously retrieved records, but only records that have been added to the database or modified since the last time they searched, they can use the type of search demonstrated in this exercise.

• open the umbrella Entrez Nucleotide database* or the Entrez Nucleotide EST - use the Preview/Index page to build your query one search term at a time



1. select the Preview/Index option beneath the search box.
   At the bottom of the Preview/Index page:
2. select the Organism field from the pop-up menu and enter mouse in the text box next to the search field menu.
   Then press the AND button to add that term and search field to the active query at the top of the page
3. select the Title field from the pop-up menu and enter actin in the adjacent text box.
   Press the AND button to add that term to the active query.
4. select the Modification Date field from the pop-up menu and enter 2002/01/20:2002/03/25 in the adjacent text box.
   Press the AND button to add that term to the active query.
5. press Go


• You can also try the same search in the Entrez CoreNucleotide or Entrez NucleotideGSS databases. If you want to use a shortcut in those databases, just copy/paste the complex Boolean query, shown below, into the query window.
  
  *At the present time, it is possible to search all three Nucleotide datasets at once, using the umbrella Entrez Nucleotide database, but this will most likely be removed in the future.

Complex Boolean query

There are four different ways you can search an individual Entrez database, as decribed in the module slides. The example above demonstrates the advanced #2 method.

The search can also be done in a single step by entering the search as a complex Boolean query. For example:

mouse[orgn] AND actin[titl] AND 2002/01/20:2002/03/25[MDAT]

Syntax for entering date ranges

Note that the syntax for entering a range of dates is date1:date2, with dates written as YYYY/MM/DD. The dates should be separated by a colon (:), which is the range operator.

You can also just enter YYYY/MM or YYYY for either or both the dates (e.g., entering 2000/05:2003 in the Modification Date field will retrieve all records that were added to the database or modified from May 2000 through the end of 2003).

Range searching on other data elements

Range searching can also be done in the following search fields -- try them in the Entrez CoreNucleotide, Entrez NucleotideGSS, or Entrez Protein databases, as appropriate/desired.

• accession       AF114696:AF114714[ACCN]       (GSS sequences)
• sequence length       3000:4000[SLEN]
• molecular weight       002002:002009[MOLWT]
• date       1998/02:2000/01/25[MDAT]
• more info in Entrez help doc