Do's and Don'ts of TSU Sampling

By Katy Holdener   |  

Do’s and Don’ts of TSU Sampling


The American Angus Association began accepting tissue-sampling units (TSU) sampling in July of 2017. As a new DNA collection method, it makes collecting DNA easier and more streamlined in comparison to traditional hair or blood sampling methods. A TSU collects an ear punch from an animal that can replace the tail hair, blood or semen sample used for DNA sampling. It is a quick and cost-effective way of collecting DNA to be used for parentage verification, genetic condition testing, genomic profiling and even bovine viral diarrhea (BVD) diagnostics. TSUs are also an effective sample method for twins.

A special applicator gun is used to punch a small bit of ear into a specialized container. The tissue is collected in seconds with a single squeeze motion with minimal stress on the animal.

Click here to find a step by step guide to collecting TSU samples, or watch this tutorial video.

As TSU sampling gains popularity, AGI representatives have noticed a few common problems were found. Below are some do’s and don’ts to successful TSU sampling:



  • Order tests through AAA Login.
  • When uploading the sample spreadsheet, include the entire barcode.
  • Email the spreadsheet to
  • Only fill in the tag number and barcode in the spreadsheet.
  • Double check to make sure the tag in the spreadsheet matches the animal.



  • Don't send in an empty vial. Make sure there is liquid in the submission.
  • Don't add your own columns in the spreadsheet. 
  • Don't put spaces in barcodes.
  • Don't write over the QR code (the barcode on the end of the sample). The barcode must be readable to scan the sample.
  • Don't put dashes and the dams tag after the calf’s tag number.
  • Don't tape the animals ID to the vial, include the information in the spreadsheet instead.


In order for your samples to be tested, the sample needs to be collected and submitted correctly.

To order a TSU sample, visit AAA Login and find the DNA tab in the menu. Navigate to the Order Tests in the small menu, and then click the bolded Order Tests. Follow instructions carefully to ensure your DNA sample is collected properly, and then submitted correctly on the spreadsheet. Double check that tag numbers match the submission before uploading.