Linear (1D) vs. 2D Barcodes for Laboratory Sample Identification



The vast majority of modern barcodes fall into 2 basic categories – linear (1D) and 2-dimensional (2D).  Some people mistakenly refer to 2D barcodes as 3D barcodes and while 3D barcodes do exist, they are generally never seen and used in life sciences.

Linear (also known as 1D or 1-dimensional) barcodes encode data using vertical bars and spaces.  The most common format in life science and clinical laboratories is Code 128 since this standard can encode all 128 ASCII characters and requires the smallest amount of space compared to other linear barcode standards.

2-dimensional (2D) barcodes use a grid pattern of data elements to encode information in both the horizontal and vertical directions.  By using both dimensions, 2D barcodes can encodes much more information in a smaller area compared to a linear barcode.  While most people are probably more familiar with the QR 2D barcode format used by websites, the standard in scientific applications is the DataMatrix format found on the bottom of Matrix, Nunc and Micronic tubes for example.

1D Barcode Advantages   

– Easier to scan since information is vertically redundant.  A “slice” of readable bars and spaces anywhere up or down the barcode is all that is needed.
– No distortion on the curved side of a tube
– More compatible with embedded scanners found in lab automation handling single tubes
– More compatible with older handheld scanners
– Compatible with clinical applications

1D Barcode Disadvantages   

– The main disadvantage of linear barcodes is size.  Since only single dimension is used to encode data, the density of 1D barcodes is dramatically less than 2D barcodes.
– Not suited for caps or bottoms of tubes due to lack of available area
– No available rack scanners

2D Barcode Advantages

– High-density encoding of information
– Well-suited for the caps and bottoms of tubes
– Error correction allows for reading of damaged codes
– Ideal for large sample collections
– Availability of rack scanners such as for Matrix or Micronic tubes

2D Barcode Disadvantages

– High-density encoding of information
– More difficult to scan.  Even with error correction each element in the barcode encodes a piece of information.
– Not well-suited for curved surfaces due to distortion or “bowtie” effect
– Fewer compatible scanners.  Legacy scanners are likely unable to read the barcode

The Bottom Line

In our experience working with customers, linear barcodes are well suited for use on the sides of tubes and when the samples are sent to a variety of destinations since they are compatible with almost all existing handheld scanners in use.  Linear barcodes are also much more widely supported for embedded barcode scanners in automated liquid handling (such as Tecan and Hamilton) and analytical instruments.

2D barcodes are ideal for internal sample storage and tracking where the labware is small and the there are a large quantity of stored samples.  The availability of rack scanners allows for quick identification of tubes with 2D barcodes on their bottom. 

 

TubeWriter 360 is a high-speed printing system for labware that dramatically reduces labeling time.  You can learn more about TubeWriter 360 here or contact us to speak about your application.

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