ESR tubes measure the rate at which red blood cells settle out of plasma. Westergren sedimentation rate tubes may be used for the standard procedure, by drawing blood in a liquid sodium citrate vacuum tube, or the modified procedure, using a saline-diluted EDTA vacuum tube.

• Precision-drawn glass and accurate calibrations ensure that the results are accurate with the standard normal values
• Manufactured from 90 expansion soda lime glass conforming to USP Type III requirements