Gel and Clot Activator Tube Tube info. Gel & Clot Activator Tube is used to obtain high quality serum specimen for clinical biochemistry, immunology and Serology Tests in clinical analysis.The tubes contain certain amount of gel at the bottom which has high thermal stability reducing the risk of clogging on testing equipment. Shelf Life 24 Months Tube Material GLASS – PLASTIC Cap Color Yellow Cap Color invert the tube from 6-8 times and centrifuge for 5-10 minutes at 1100-1500 RPM after 10 to 30 minutes coagulation. Available Sizes