FDA's mobile laboratories are part of the agency's nationwide network of laboratories, where scientists are continually testing food and drugs for contaminants. The chemistry mobile lab is shown here on the road near its base of operations in Jefferson, Ark.

This modified 44-foot trailer is one of three units that make up FDA's chemistry mobile laboratory.

This 34-foot command center, outfitted in a modified motor home, is part of FDA's chemistry mobile laboratory. Two other units, the sample preparation unit and the analytical unit, complete the lab.

An FDA scientist, who doubles as a driver, loads cable covers into the chemistry mobile laboratory. The covers protect communication cables, water hoses, and other cabling necessary to run the lab equipment.

An FDA scientist/driver replaces the generator cover of the mobile laboratory command center. The mobile lab runs on generators, carries its own water, and holds waste water in on-board tanks to prevent any release into the environment.

FDA scientists/drivers discuss the placement of the mobile laboratory units in the convoy for road travel.

In Salinas, Calif., an FDA consumer safety officer collects lettuce samples in a grower's field. The samples will be taken to FDA's mobile laboratory where they will be tested for harmful bacteria.

An FDA scientist scans a bar code into a tracking database in the mobile laboratory's command center. Bar codes correspond to samples collected for testing. Replacing the paper system with bar codes streamlines the operation of entering data, tracking samples, and sharing test results.

An FDA scientist examines a lettuce sample in the sample preparation glove box. The sterile box protects the sample from being contaminated by the scientist's hands, and also protects the scientist from any potentially harmful substances in the sample.

A lettuce sample is weighed in a sterile bag in the microbiology mobile laboratory's sample preparation unit.

An FDA scientist places a lettuce sample into the grinder (background). Another scientist prepares the centrifuge (foreground), which spins samples to separate particles in preparation for testing.

FDA scientists add enrichment broth to a sample rinse solution. The broth contains a mixture of food for bacteria in the sample to eat and grow.

An FDA scientist places a sample contained in an enrichment broth into an incubator to grow overnight. Antibiotics will be added to the sample to suppress bacteria that are not harmful. Once these competing bacteria are reduced, any harmful organisms, such as Salmonella, can be more easily detected

Now ready for testing, the incubated, enriched sample is carried from the microbiology mobile laboratory's sample preparation unit to the analysis and testing unit.

An FDA scientist transfers tubes containing DNA extraction buffer and a sample from the heating block in the mobile laboratory's analytical unit. Extraction of DNA from the sample's cells is an early step in detecting bacteria.

An FDA scientist loads tubes containing a sample's DNA into an instrument that amplifies and detects the DNA of harmful bacteria.

In the mobile laboratory's command center, scientists enter sample test results into FDA databases. Electronic worksheets allow rapid sharing of results with FDA's fixed laboratories or other government laboratories.

FDA's mobile laboratory returns from a testing mission to its home base in Jefferson, Ark.

See the full article about FDA's Mobile Laboratory on FDA.gov/consumer

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