Avoid Green Top Tubes for Canine Progesterone Testing At All Costs!

Why You Should Avoid Green Top Tubes for Canine Progesterone Testing

At K9Reproduction, we're committed to providing breeders with the best tools for successful canine progesterone testing. One critical issue we often encounter is the misuse of green top tubes (lithium heparin) in progesterone testing, which can lead to inaccurate results and jeopardize your breeding program. This page explains why using green top tubes for progesterone testing is a mistake and offers the proper supplies you need for reliable results.

Watch our detailed video explaining why green top tubes shouldn’t be used: Watch our warning about green top tubes here

What Are Green Top Tubes and Why Are They a Problem?

Green top tubes contain heparin, an anticoagulant that prevents blood from clotting. While heparin is useful for certain types of blood tests, it’s not appropriate for progesterone testing. Here’s why:

1. Serum vs. Plasma: For accurate progesterone readings, you need serum—the liquid portion of the blood that remains after clotting. Plasma, which is what you get when using green top tubes, still contains clotting factors, which can interfere with the test and lead to false results.

2. Inaccurate Readings: The presence of clotting factors in plasma can skew progesterone levels, leading to incorrect timing for breeding, which may result in failed attempts.

What Should You Use Instead?

To ensure accurate progesterone testing, it’s essential to use tubes that allow the blood to clot and produce serum. These include:

• Red Top Tubes: These have no additives and allow the blood to clot naturally.

• Serum Separator Tubes (SST): These tubes have a gel that separates the serum from the blood cells during centrifugation.

• Regular Empty Centrifuge Tubes: Also a reliable option when handled correctly, allowing proper serum collection.

What Causes Stuck-Together Platelets?

When blood is drawn and spun in a centrifuge, the goal is to separate the serum or plasma from the cells. However, sometimes platelets stick together, creating a jelly-like substance. This often happens when:

• Incomplete Clotting: If the blood hasn’t fully clotted before centrifugation, platelets can remain suspended in the serum or plasma, leading to an unclear sample.

• Improper Centrifugation: Using the wrong speed or centrifugation time can prevent the serum from properly separating, resulting in clumping.

Solution: You can often resolve this by mixing the sample and re-spinning it. In most cases, this will separate the platelets and yield a clear serum sample.

Why Serum is Preferred for Progesterone Testing

Serum is the gold standard for progesterone testing because it’s free from clotting factors, unlike plasma. According to LabCorp and the NCBI, serum provides the most stable environment for hormone assays like progesterone. The absence of clotting factors ensures that the test results are accurate and reliable.

• Learn more about the difference between serum and plasma from LabCorp here:
  LabCorp Plasma vs Serum Guidelines

• Read more about the role of serum in hormone testing from the NCBI here:
  NCBI Article on Serum vs Plasma

Beware of Sellers Promoting Green Top Tubes

Unfortunately, some sellers in the market are offering green top tubes for progesterone testing, which shows a lack of understanding of the process. Using these tubes can lead to false results and unsuccessful breedings. At K9Reproduction, we are experts in this field, and we provide only the best and most appropriate supplies for accurate progesterone testing.

Frequently Asked Questions

Q: Can I fix jelly-like serum or plasma after centrifugation?
A: Yes, if the serum or plasma appears jelly-like after centrifugation, gently mix the sample and re-spin it to achieve better separation.

Q: Why is serum preferred for progesterone testing over plasma?
A: Serum is free from clotting factors, ensuring more accurate test results, while plasma contains clotting agents that can interfere with the test.

Q: What happens if I use green top tubes for progesterone testing?
A: Green top tubes will result in plasma rather than serum, which can produce inaccurate progesterone levels, leading to mistimed breedings.

Conclusion: Trust the Experts for Accurate Testing

When it comes to your breeding program, accuracy is everything. Using the wrong supplies, like green top tubes, can lead to costly mistakes. Stick with K9Reproduction, the trusted source for all your progesterone testing needs, and rest assured that you’re getting the best tools for success.

For more information, watch our video warning against green top tubes: Watch our warning about green top tubes here