These medical-grade, autoclavable 20mm glass test tubes feature black threaded, rubber-lined caps. Heavy-duty screw-tops have a deep thread finish for an extra twist of security. Use in lab to store mushroom cultures, laboratory samples, and more. 

Made from Type I Borosilicate glass, test tubes have a low temperature gradient and can withstand direct flame, high temperatures and thermal shocks. 

Made in the USA.

Need a test tube rack? You can find it here.