Greiner Bio-One Vacuette Venous Blood Collection Tube Plain 13 X 100 mm 6 mL White / Black Ring Pull Cap Polyethylene Terephthalate (PET) Tube - 456085

I looked all over the Internet for cheaper bottles and some people are charging upwards of $100 for a small amount of bottles these are a little bit smaller on the 6ml side rather than the 10ml - but they worked first time - you have to have them spinning within 90seconds after drawing blood to keep it liquid for injections. You get about 10-30 of it being liquid. Red capped glass bottles did not work and they coagulated every single time when I pulled them out of the centrifuge!! These worked perfectly! 700/800g spinning with a 7-12min protocol for C-PRF