The HSP70 ELISA kit (ADI-EKS-700B) was designed to measure HSP70 in cell and tissue lysates, and is not typically sensitive enough for serum or plasma. It is for this reason that the HSP70 High Sensitivity ELISA kit (ADI-EKS-715) kit and the AMP’D® HSP70 high sensitvity ELISA kit (ENZ-KIT-101) were created. If you have samples that you know will have high amounts of induced HSP70, there is no reason not to use the ADI-EKS-700B kit; there should not be compatibility issues with your sample type as long as there is enough there to detect. Please be aware that the AMP’D® high sensivity HSP70 ELISA kit (ENZ-KIT-101) can detect both baseline and upregulated levels of HSP70.