The MDT Modular Reservoir Dynamics Tester measures reservoir pressure quickly and accurately, collects representative fluid samples from multiple layers, and provides permeability and anisotropy data through a variety of interval pressure transient tests. The MDT tool can also be used to conduct a mini-frac test to obtain the minimum in situ horizontal stress in several layers. Live Fluid Analyzer (LFA) The LFA live fluid analyzer module of the MDT modular formation dynamics tester minimizes the pumping time to acquire representative reservoir fluid for both downhole fluid analysis (DFA) and sample acquisition for laboratory analysis. The contents of the flowline are optically scanned to reliably detect water and oil via real-time spectroscopy and track contamination. The LFA analyzer’s gas refractometer differentiates between gas and liquid.