| Acronym | Meaning |
 | MDHS | Methods For The Determination Of Hazardous Substances |
 | MDI | Methylene Di-p-phenylene Isocyanate |
 | MDI | Modified Dipole Interaction(model For Mol.-polarizability Calcn.) |
 | MDL | Method Detection Level Or Limit |
 | MDLC | Multidimensional Liquid Chromatography |
 | MDMI | Monodisperse Dried Microparticulate Injector |
 | MDO | Max. Degree Of Order |
 | MDPE | Medium-density Polyethylene |
 | MDQ | Minimum Detectable Quantity |
 | MDR | Multidrug Resistance |
 | MDS | Matrix-diagonalization Sudden Approximation (for Atom Surface Scattering Calcns.) |
 | MDS | Metastable Deexcitation Spectroscopy |
 | MDS | Minimum Detectable Signal |
 | MDSC | Modulated Differential Scanning Calorimetry |
 | MDSRS | Morphology-dependent Stimulated Raman Scattering |
 | MDV | Marek's Disease Virus |
 | MDW | Mixed Density Wave |
 | MDW | Multichannel Distorted Wave (Born Approxn.) |
 | MEAN | Multipole-extracted Adiabatic-nuclei (for Electron-molecule Collisions) |
 | MEBES | Micro-electron Beam Evaporation Source |
 | MEBS | Medium Energy Backscattering Spectrometry |
 | MECA | Molecular Emission Cavity Analysis |
 | MECA | Multiple Excitation Collisional Activation |
 | MECC | Micellar Electrokinetic Capillary Chromatography |
 | MECI | Monoexcited Configuration Interaction |
 | MECI | Multielectron Configuration Interaction |
 | MECOP | Modified Electron Correlation Polarization (potential) |
 | MECS | Manufacturing Energy Consumption Survey (DOE) |
 | MED | Mean Effective Dose |
 | MED | Minimal Erythema Dose |
 | MEDLA | Molecular Electron Density Lego Assembler |
 | MEDLARS | Medical Literature Analysis And Retrieval System (NLM) |
 | MEDO | Multipole Expansion Of Diatomic Overlap Approximation |
 | MEDOC | Multipole Expansion Defined (on) One Center (a Wave Function In Calcns. On Atomic And Molecular Collisions) |
 | MEE | Migration-enhanced Epitaxy |
 | MEECC | Microemulsion Electrokinetic Capillary Chromatography |
 | MEED | Medium-energy Electron Diffraction |
 | MEEKC | Microemulsion Electrokinetic Chromatography |
 | MEF | Mouse Embryonic Fibroblast |
 | MEF | Myocyte Enhancer Factor |
 | MEG | Mixed Exponentially Generated (wave Function) |
 | MEG | Modified Electron Gas (quantum Calcn. Method) |
 | MEG4 | Multiexponentially Generated 4 (wave Functions) |
 | MEHT | Modified Extended Hueckel Theory |
 | MEI | Maximally Exposed Individual |
 | MEIA | Microparticle Enzyme Immunoassay |
 | MEIS | Medium Energy Ion Scattering |
 | MEK | Methyl Ethyl Ketone (butanone) |
 | MEKC | Micellar Electrokinetic Chromatography |
 | MEKP | Methyl Ethyl Ketone Peroxide |