• CAplus -
  >32 million references
  
  SciFinder also includes 
• MEDLINE -
  >18 million references

• >54 million organic and inorganic substances
• >62 million sequences (view latest numbers)

• >39 million single- and multi-step reactions, and synthetic preparations

• >275,000 inventoried or regulated chemicals

• >41 million commercially- available products

Chemistry and chemistry-related articles covering topics such as

• Proteomics
• Genomics
• Biochemistry
• Biochemical genetics
• Organic
• Macromolecular
• Applied
• Physical, inorganic, analytical

MEDLINE - Produced by NLM, and covers all areas in the broad field of biomedicine

Information about the many different types of substances, including

• Synonyms
• Molecular formulas  
• Ring analysis data
• Structure diagrams
• Experimental and predicted property data
• Literature references

Reaction information consisting of

• Structure diagrams for reactants and products
• CAS Registry Numbers for all reactants, products, reagents, solvents, and catalysts
• Detailed reaction conditions

Chemical substances that are regulated in key markets across the globe:

• Chemical names
• Synonyms
• Regulatory lists
• Chemical inventory status

Information about commercially- available chemicals and their suppliers:

• CAS Registry Number 
• Supplier information
• Quantities
• Prices

CAplus

• Early 1800s to present 
• More than 10,000 scientific journals worldwide
• More than 1,500 key chemical journals
• Patents from 61 patent authorities (see CAS Coverage of Patents)
• Conference proceedings
• Technical reports
• Books
• Dissertations
• Reviews
• Meeting abstracts
• Electronic-only journals
• Web preprints

MEDLINE

• 1947 to present
• 4,800 biomedical journals
• 99% of references are from journal literature
• 1947-1965 from OLDMEDLINE database

• Substances from journal articles, patents, chemical catalogs, and reputable web sources from the early 1800s to present  
• GenBank sequences
• Organic substances as well as
  - Alloys
  - Coordination  compounds
  - Minerals
  - Mixtures
  - Polymers
  - Salts
  - Sequences
  - Organo-
    metallics
  - Proteins
  - Inorganic substances
  

• 1840 to present
• Reactions from journals, patents, and dissertations, as well as from evaluated reference works

• Originally from data in the 1985 TSCA inventory and supplements
• U.S. Government Federal Register 1778-1987
• Thirteen national inventories
• State lists

(view lists)

• >1,000 suppliers of commercial chemicals worldwide
• >1,100 chemical catalogs

CAplus - 3,000 references daily

MEDLINE - 5 times per week