English: SST en:vacutainer spun down, with some serum already removed.
This picture shows the three layers of blood cells, gel separater, then serum.
This is an SST II tube, the gel is clearer and more colourless than the old SST tubes. It's meant to affect drug concentrations less than the original.
{{BotMoveToCommons|en.wikipedia|year={{subst:CURRENTYEAR}}|month={{subst:CURRENTMONTHNAME}}|day={{subst:CURRENTDAY}}}} {{Information |Description={{en|SST en:vacutainer spun down, with some serum already removed. This picture shows the three layers