The saliva collection tube must be sterile and it must have dimensions which are conducive for contamination-free extraction of the saliva sample using a filtered pipette tip.
The ideal specimen collection tube for a SalivaDirect test sample should be wide enough to collect the patient sample, deep enough to hold sufficient sample to obtain a robust pool of RNA, but not too deep to make it challenging to remove the sample without contacting the tube walls.
These requirements pose difficulties when considering one of the many typical sterile centrifuge tubes found in research laboratories.
1.5mL or 2.0mL tubes may not hold enough sample and are difficult for the patient to cleanly provide a sample.
50mL tubes have the correct girth to easily collect enough sample, but at 117mm deep they require a deft hand and nearly impossible to find 1000mL extra-long filter tip pipette tips to remove the sample for processing.
For these reasons, a variety of 5mL tubes have become the go-to sample collection tube for SalivaDirect Testing because they offer the closest match to meet these criteria.
5mL plastic culture tubes, 5mL glass tubes and 5mL screw-cap centrifuge tubes as well as other varieties.
But the fit has not been without issues.
For a mess-free collection of patient saliva some form of sterile funnel is still needed to plant the sample into the 5mL tube and not down the outer walls, but sterile funnels are not easy to come by.
A solution to effective contamination free saliva sample collection may be these new 25mL sterile centrifuge tubes.
Designed to match the girth of a typical 50mL conical tube but at two-thirds the height, there is plenty of room for easy sample collection for the patient and lab technician alike.
The leak-tight caps close with a quick twist and the 25mL tube dimensions make it easy to grip securely for a quick vortex to break open cellular components and extract the RNA.
Beyond COVID-19 testing these 25mL sterile conical tubes can be used wherever a 50mL tube can thanks the to reinforced lip which supports the tube when used in a 50mL centrifuge rotor.
Reducing laboratory waste is a mission we can all get behind. A 25mL tube that can do the work of a 50mL tube will be a welcome addition to any laboratory.
Clinical laboratories, colleges, universities and anyone conducting SalivaDirect testing will immediately see the value in these sterile 25mL tubes which can be bought pre-racked for the fastest deployment.