• Histochemical tracer
  Histochemical tracer
  A histochemical tracer is a compound used to reveal the location of cells and track neuronal projections. A neuronal tracer may be retrograde, anterograde, or work in both directions...
  
  , a substance used for tracing purposes in histochemistry, the study of the composition of cells and tissues
• Isotopic tracer, a substance with an isotope that has been enriched to a greater level than that found in nature
• Radioactive tracer
  Radioactive tracer
  A radioactive tracer, also called a radioactive label, is a substance containing a radioisotope that is used to measure the speed of chemical processes and to track the movement of a substance through a natural system such as a cell or tissue...
  
  , a substance containing a radioisotope that is used for tracking purposes
• Flow tracer
  Flow tracer
  thumb|right|300px|On May 2, [[2001]], the Moderate-resolution Imaging Spectroradiometer obtained this spectacular image of the [[Atlantic Ocean]]'s [[Gulf Stream]]. The [[false color]]s in the image represent "[[brightness temperature]]" observed at the top of the [[atmosphere]]...
  
  , any fluid property used to track fluid motion:
  • Dye tracer
  • In the ocean, salinity
    Salinity
    Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
    
    , potential temperature, and the concentration of many different chemical compounds
• Tracer ammunition
  Tracer ammunition
  Tracer ammunition are bullets that are built with a small pyrotechnic charge in their base. Ignited by the burning powder, the phosphorus tail burns very brightly, making the projectile visible to the naked eye...
  
  , special bullets that burn brightly to enable the shooter to follow the bullets' trajectories
• Mercury Tracer
  Mercury Tracer
  The Mercury Tracer is a compact car that was sold by the Mercury division of Ford Motor Company. It was based on the platform of the Mazda 323, replacing the European-derived Mercury Lynx. The 1991 and newer car is the Mercury version of the Ford Escort....
  
  , an automobile
• TRACER (cosmic ray detector)
  TRACER (cosmic ray detector)
  Transition Radiation Array for Cosmic Energetic Radiation is a balloon flown cosmic ray detector built and designed at the University of Chicago. The detector is designed to measure the energy spectra of cosmic ray nuclei with atomic numbers between five and twenty-six .-External links:* on the...
  
   (Transition Radiation Array for Cosmic Energetic Radiation), a balloon-borne cosmic ray detector
• TRACER
  Tactical Reconnaissance and Counter Concealment Enabled Radar
  The United States Army Tactical Reconnaissance and Counter Concealment Enabled Radar - TRACER is a mid-range, long wavelength synthetic aperture radar system that provides all-weather persistent surveillance developed by the United States Army Communications-Electronics Research, Development and...
  
   (Tactical Reconnaissance and Counter Concealment Enabled Radar) is a mid-range, long wavelength synthetic aperture radar system developed by the United States Army.

Entertainment

• Tracer (DC Comics), a DC Comics
  DC Comics
  DC Comics, Inc. is one of the largest and most successful companies operating in the market for American comic books and related media. It is the publishing unit of DC Entertainment a company of Warner Bros. Entertainment, which itself is owned by Time Warner...
  
   character
• Tracer (Marvel Comics)
  Tracer (Marvel Comics)
  Tracer is a fictional character, a supervillain in the Marvel Comics Universe, in which he is an enemy of Spider-Man. His first appearance was in Friendly Neighborhood Spider-Man #1.-Fictional character biography:...
  
  , a Marvel Comics
  Marvel Comics
  Marvel Worldwide, Inc., commonly referred to as Marvel Comics and formerly Marvel Publishing, Inc. and Marvel Comics Group, is an American company that publishes comic books and related media...
  
   supervillain
• Tracer (Transformers), a fictional character.

See also

• Trace (disambiguation)
• Tracing (disambiguation)
• Tracker (disambiguation)
  Tracker (disambiguation)
  Tracker may refer to:* Tracking , a specialization in finding and following a trail* Track and field athletes, particularly those in track events* Tracker action, in music, a form of mechanics used in certain pipe organs...
  
  
• Tracer use in the oil industry
  Tracer use in the oil industry
  Tracers are used in the oil industry in order to qualitatively or quantitatively gauge how fluid flows through the reservoir, as well as being a useful tool for estimating residual oil saturation. Tracers can be used in either interwell tests or single well tests...
  
  
• Traceur, a male parkour practitioner
• Tracer
  Tracer (bus)
  Tracer is the public bus system for the city of Tracy, California, USA and the bus system is unique in that since 2002 every April and December the buses are 100% free to all riders.-Operations:...
  
  bus system