DNA & Tissue Sampling Devices Category Guide

What Are Tissue Sampling Devices?

Tissue sampling devices are tools used to collect DNA samples from cattle for genomic testing and parentage verification. The most common methods involve collecting small tissue samples from the ear during tagging, or gathering hair samples with intact follicles. Proper sample quality is essential for accurate laboratory analysis.

Types of Sampling Methods

Tissue Sampling Units (TSUs)

Small devices that collect a tissue sample when applied to the ear, often simultaneously with ear tag application. The tissue is preserved in a buffer solution for laboratory analysis. TSUs are the most efficient method for large-scale genomic testing programs.

Hair Cards

Cards designed to collect hair samples with intact follicles from the tail switch or ear. Hair cards are inexpensive and don't require special ear tag applicators, but proper collection technique is critical for sample quality.

Blood Samples

Occasionally used for genomic testing when tissue or hair samples aren't available. Requires veterinary collection and proper handling. More expensive and less common than other methods.

Best Practices for Sample Collection

• Follow manufacturer protocols: Each testing company has specific collection requirements
• Maintain sample integrity: Keep samples at recommended temperatures and avoid contamination
• Accurate identification: Match samples to correct animal IDs—mislabeled samples waste time and money
• Timely submission: Send samples promptly; degraded DNA affects result quality
• Proper storage: Store samples as directed until submission

Choosing Sampling Equipment

Consider these factors when selecting sampling devices:

• Compatibility with your ear tag system
• Laboratory requirements for your testing company
• Ease of use during tagging protocols
• Sample preservation method and shelf life
• Cost per sample including shipping

When to Collect Samples

Most farms collect DNA samples at birth during initial ear tagging. This allows genomic test results to inform heifer selection decisions as early as possible. Samples can also be collected from older animals when genomic information is needed for breeding decisions.

Cost Considerations

Tissue sampling units typically cost $1-3 per device when purchased in bulk. Hair cards are less expensive ($0.25-0.50 each) but require more collection time. Factor in shipping costs and consider testing lab requirements when budgeting for sample collection supplies.