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and also the value of your results. For this purpose MEDLINE, the online version of the

library at the National Institute of Health, is an indispensable tool. A large, worldwide

open library about medicine and biology:

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MEDLINE (or also PubMed)

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https://www.ncbi.nlm.nih.gov/pubmed

It is the online version of the library. Only here, in Betheds (near Washington), the

Health Research Center of the United States of America, has it been possible to keep a

sufficiently large staff of service scientists permanently on hand to ensure easy use of the

web pages and to keep the data constantly up to date. This is a truly extraordinary achieve­

ment, which is precisely why it looks and feels child’s play to use.

Here you can search for keywords (“HIV”, “sequence analysis”, “aging”), for authors

(“Dandekar-T”, “Kunz-M”), journals (“Nature”, “Science”). For each article found, a

table of contents will then appear, but also links to related articles (including search

options). A steadily increasing number of articles also offer a directly readable full-text

link (“Open Access  ”, even for current articles already more than 30%, for articles one to

2 years old it is now even the majority). It is possible for the experienced to search for an

article much more precisely and with many more criteria (“advanced search”). It is helpful

to have a look at the PubMed tutorials or our tutorial in the appendix. In addition, PubMed

also provides important textbooks online and a variety of other resources.

How Do I Get the Sequence to My Molecule?

Many bioinformatics studies start with the sequence of a molecule and analyze it.

Interestingly, this important starting information, i.e. what sequence the molecule I am

interested in has, is already known for many millions of entries. This is especially true for

important organisms such as humans, the bacterium Escherichia coli (E. coli), plants such

as Arabidopsis, mice, the worm Caenorhabditis elegans (C. elegans), and the fruit fly

Drosophila melanogaster. To check if my sequence for this protein or term is already

known, look it up at NCBI in particular. If it is known, the sequence for DNA, RNA

(option “nucleotide” or “gene”) or proteins (option “protein”) can easily be found here,

e.g. for “HIV” there are hundreds of thousands of entries:

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https://www.ncbi.nlm.nih.gov/protein/?term=hiv

One of the first offers from the long list of hits is an artificial sequence for the “TAR

protein”:

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https://www.ncbi.nlm.nih.gov/protein/AAX29205.1

The now mostly quite long header entry explains already existing information about the

respective protein:

1.1  How Do I Start My Bioinformatics Analysis? Useful Links and Tools