A bar-code system (see figure) has been assembled for a microbiological laboratory that must examine a large number of samples. The system includes a commercial bar-code reader, computer hardware and software components, plus custom-designed database software. The software generates a user-friendly, menu-driven interface.

Traditionally, microbiological samples have been labeled by hand, and recording of results of microbiological assays has entailed handwriting of bacterial colony counts in notebooks. This traditional approach is both time-consuming and susceptible to human error, especially when large numbers of samples are involved. By automating the routine aspects of tracking microbiological samples, recording data, and documentation of samples and results, the bar-code system saves time and greatly reduces the incidence of errors.

The Bar-Code System Hardware includes a personal computer, a desktop bar-code scanner (on the right by tubes and plates), and a PDA with a built-in bar-code scanner (left of the keyboard).

The bar-code system prints unique bar-code labels that can be easily affixed to test tubes and Petri dishes. During sampling, a technician or microbiologist affixes the labels and uses a personal digital assistant (PDA) with a built-in bar-code scanner to scan the bar codes and record notes. After sampling, the data acquired by the bar-code scanner are downloaded to the bar-code-system database, and then a microbiologist assays the samples.

To record assay results, the microbiologist scans the barcode label on each test tube or Petri dish and records the data specific to that sample container on an interactive computer display in a location reserved for those specific data. Inasmuch as the database software is designed to display only the record that corresponds to a given bar code, the possibility of accidentally recording data in the wrong place is eliminated (except, of course, for rare instances of computer error or errors in re-affixation of labels that have fallen off). In addition, because the microbiologist no longer needs to painstakingly find the correct place to enter data for each assay plate, the barcode system accelerates the process of reading plates and recording data.

The bar-code system greatly simplifies the documentation of the sampling process. During sampling, the note-taking capability of the PDA is complemented by the use of a digital camera: The sampling technician or microbiologist takes a picture of each sample and records the picture number (as assigned by the digital camera) in the PDA. Once the data and pictures are downloaded to the database, only a few mouse clicks are necessary to generate a two-column report that displays the pictures in one column and lists the corresponding samples and pertinent information in the other column. In addition, the bar-code system automatically generates a report of assay results. The data in the report can be exported to a spreadsheet for analysis.

This work was done by Jennifer Law and Larry Kirschner of Caltech for NASA's Jet Propulsion Laboratory. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Electronics/Computers category. NPO-30815


This Brief includes a Technical Support Package (TSP).
Bar-Code System for a Microbiological Laboratory

(reference NPO-30815) is currently available for download from the TSP library.

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This article first appeared in the May, 2007 issue of NASA Tech Briefs Magazine.

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