Microscale Thermophoresis (MST) Lab
Model Soret effect thermophoretic depletion, temperature-jump fluorescence, in-lysate screening, binding isotherms, KD titrations, and lab DCF.
MST Assay Parameters
Live SolverMST Facility Budget
10-Yr Cash FlowTime-Resolved Microscale Thermophoresis Traces
Real-time fluorescence response: Initial state, T-jump, and Soret thermophoretic migrationEquilibrium Binding Isotherm (Fnorm vs [Ligand])
Non-linear quadratic regression fit across 16 capillary dilution points with error barsMST Testing Core Facility — 5-Year Pro-Forma DCF
Comprehensive analytical testing revenue, capillary consumables, warranty, depreciation, and cash flows| Metric ($) | Year 1 | Year 2 | Year 3 | Year 4 | Year 5 |
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1. Ludwig-Soret Thermophoresis Physics
Molecules in a liquid thermal gradient migrate away from the heat source along a concentration gradient:
The Soret coefficient ST is proportional to the difference in hydration entropy Δshyd and effective surface charge density. Ligand binding directly perturbs the hydration shell, altering thermophoretic velocity and producing an unambiguous binding signal.
2. Free-Solution & In-Lysate Matrix Tolerance
Unlike surface-tethered biosensors (SPR, BLI), MST operates in free solution within glass capillaries:
Target proteins do not undergo surface denaturation or steric hindrance. Fluorescent fusion tags (e.g. GFP or RED-tris-NTA) permit affinity screening directly inside unpurified cell lysates, validating drug targets under physiological intracellular conditions.
3. Normalized Fluorescence & KD Fitting
MST signals are normalized as the ratio of hot fluorescence to cold baseline fluorescence:
Fitting Fnorm against ligand concentration with a non-linear quadratic model directly yields the equilibrium dissociation constant KD. For PROTAC ternary complexes, the cooperativity factor α = KD1 / KD2 is easily resolved.
4. Testing Facility Economics & Throughput
MST provides rapid 15-minute turnaround per 16-capillary titration with minimal sample consumption (4 µL per capillary):
With low consumable costs and negligible maintenance overhead compared to mass spectrometry or cryogenic TEM, an MST core lab delivers exceptional operating margins while serving as an indispensable hit validation engine.
Frequently Asked Questions
c/c0 = exp(−S_T · ΔT). The Soret coefficient (ST = DT / D) depends on the molecule's hydrodynamic radius, effective surface charge density, and surrounding hydration water structuring, making it exquisitely responsive to subtle conformational changes and binding events.