Beginning Monday, October 15th at 8 AM the tube type required for D-Dimer will change from a Sodium Citrate tube (blue top) to a PST gel tube (light green top). General stores order# MH09034. This is the tube used for routine chemistries. The blue top tube will no longer be acceptable. This will obviate the need to draw a separate tube for the D-Dimer assay. Questions to R. Feld at 6-1759.