screening
    n 1: the display of a motion picture [syn: screening,
         showing, viewing]
    2: fabric of metal or plastic mesh
    3: the act of concealing the existence of something by
       obstructing the view of it; "the cover concealed their guns
       from enemy aircraft" [syn: cover, covering, screening,
       masking]
    4: testing objects or persons in order to identify those with
       particular characteristics

Screening \Screen"ing\ (skr[=e]n"[i^]ng), n.
   the process of examining or testing objects methodically to
   find those having desirable properties. See screen[3].

   Note: In the pharmaceutical industry, pharmaceutical
         screening involves testing a large number of samples of
         substances to find those having desirable
         pharmacological activity; those samples which have the
         property sought are called active or positive in the
         screen. The substances tested may be pure compounds
         with known structure, mixtures of pure compounds, or
         complex mixtures obtained by extraction from living
         organisms. There are often additional sets of test
         performed on active samples, called

   counterscreening to eliminate those samples that may also
      possess undesirable properties. In the case of screening
      of mixtures from living organisms, a type of
      counterscreening called dereplication is usually
      performed, to determine if the active sample contains a
      known compound which has previously been studied.
      [PJC]

Screen \Screen\ (skr[=e]n), v. t. [imp. & p. p. Screened; p.
   pr. & vb. n. Screening.]
   1. To provide with a shelter or means of concealment; to
      separate or cut off from inconvenience, injury, or danger;
      to shelter; to protect; to protect by hiding; to conceal;
      as, fruits screened from cold winds by a forest or hill.
      [1913 Webster]

            They were encouraged and screened by some who were
            in high commands.                     --Macaulay.
      [1913 Webster]

   2. To pass, as coal, gravel, ashes, etc., through a screen in
      order to separate the coarse from the fine, or the
      worthless from the valuable; to sift.
      [1913 Webster]

   3. to examine a group of objects methodically, to separate
      them into groups or to select one or more for some
      purpose. As:
      (a) To inspect the qualifications of candidates for a job,
          to select one or more to be hired.
      (b) (Biochem., Med.) to test a large number of samples, in
          order to find those having specific desirable
          properties; as, to screen plant extracts for
          anticancer agents.
          [PJC]