It only amounts to about 4 bucks a test. I use the vaccum. I hold the vaccum cup in my right hand with the needle coming out the bottom of my grip. When I see blood on the needle, I push the tube in with my thumb.
I had 3 hold over heifers from the cows that calved last spring. They are now rolled to fall. They were 14 months old in May. I bred all 3 to AI bulls using natural heats.
I have confirmed all three bred. I used the BioPRYN tubes. I had one tube that I had trouble with. I may have lost the vacuum. What amazed me was how small a sample they can run. Bigfoot had a picture of a small sample. Like his, I got my confirmed bred based on only the bottom of the tube being covered.