MSE ^E The simultaneous acquisition of exact mass data using alternating collision cell energies. This technique is unique to Waters mass spectrometers, which can perform this simultaneous data capture at UPLC speed (see also UPLC). The MSEE approach, when used to acquire precursor and product ion information, has the additional benefits of obtaining both types of data in one analytical run. Both the precursor and product ion data are acquired in accurate mass mode so that elemental composition information can be generated from both sets of data. Another advantage of MSE^E is that neutral loss information from a comparison of the two alternating collision energy scans can be obtained, eliminating the need for any further experimentation. The mode of operation also removes the need for time-consuming reanalysis to obtain both MS and MS/MS data. Data acquired in MSE^E mode can be mined at a later date for different information.

multicellular Referring to organisms composed of more than one cell—often billions of them—arranged in various organs, tissues, and systems.

multimer Any small polymer; in bio-pharmaceuticals, usually a protein made up of more than one polypeptide chain.

mutagen An agent (chemicals, radiation) that reacts with DNA to produce mutations.

mutagenicity The degree to which a substance can cause a change in an organism's DNA.

mutation A permanent change in DNA sequence or chromosomal structure.

MW molecular weight; refers to the mass of a molecule, usually stated in Daltons.

mycoplasma Parasitic microorganisms that infect mammalian cells, possessing some characteristics of both bacteria and viruses. Prokaryotic microorganisms, family Mycoplasmataceae, with no cell walls (therefore resistant to many antibiotics) and needing sterols for maintenance and growth. Potential contaminants of mammalian cell cultures, they may grow attached or close to cell surfaces in the cytoplasm, subtly altering properties of the cells, but escaping detection unless specifically monitored. In cell culture of biopharmaceuticals, each lot must be tested at the end of cell culture for mycoplasma contamination; a confirmed positive results in batch rejection.

myeloma Lymphocytic cancer; a malignancy found in bone marrow.

N

native The natural state; in a biopharmaceutical context, it usually refers to a molecule's normal three-dimensional structure under optimal conditions.

NDA New Drug Application; CDER's equivalent of the BLA. It is used for small-molecules and some biopharmaceuticals (such as hormones and small peptides), which are regulated by CDER rather than CBER.

nebulizer A device, pressurized by an oxygen or nitrogen tank, for the purpose of converting a liquid (such as a medicinal formulation) into a fine mist (to be inhaled, for example).

nick translation A technique used to introduce radioactively and nonradioactively labeled nucleotides into DNA; the new nucleotide is added at the position where the original nucleotide was excised; nick translation can be used for a number of hybridization techniques, such as gel blots and colony plaque lifts.

NIH National Institutes of Health; the US government agency that conducts and supports medical research and dissemination of information. One of eight agencies in Public Health Services, which is in turn part of the US Department of Health and Human Services.

NIR spectroscopy Near-infrared spectroscopy; a bioanalytical technique that uses radiation in the near-infrared range to provide rapid, nondestructive analysis of materials.

NIST National Institutes of Standards and Technology; a federal agency that develops and certifies standard reference materials for use in various US industry applications