microcarrier A microscopic particle (often a 200 μm polymer bead) that supports cell attachment and growth in suspension culture; alternative
to microencapsulation. Cells anchor into tiny pores on the beads for protection.
microencapsulation In cell culture, trapping cells inside a thin protective membrane to provide anchorage and protect them from harsh conditions.
Microspheres are often biodegradable.
microfiltration A method of sterile filtration, clarification, or cell harvesting that removes particles in the 0.1 to 10.0 μm range.
microheterogeneity In biopharmaceuticals, usually small differences in the amino acid sequence or structure of a polypeptide chain. For example,
to produce a recombinant protein in E. coli, a Met must be added to one end of the protein sequence to act as a signal that initiates protein synthesis. In most cases,
that Met is removed once the protein is made. Sometimes the Met is removed from only some of the molecules. The purified product
is then a mixture of a protein with the native sequence and a protein with the native sequence plus the extra amino acid.
microinjection Manually using tiny needles to inject microscopic material (such as DNA) directly into cells or cell nuclei; video screens
provide a magnified view.
micron See μmeter. The preferred term is micrometer.
μmeter One millionth of a meter's length. Abbreviated as μm.
microorganism A microbe; a free-living organism too small to be seen by the naked eye.
microspheres Tiny polymer spheres (usually biodegradable) measured in micrometer.
miRNA A single-stranded RNA molecule of about 21 to 23 nucleotides in length, which regulates gene expression.
mitochondria Animal-cell organelles that reproduce using their own DNA. They metabolize nutrients to provide the cell with energy and are
believed to have once been symbiotic bacteria. Chloroplasts are their plant-cell equivalents.
MOBCAL Software that calculates mobilities. MOBCAL is an open-source software and is command-line driven (http://www.indiana.edu/~nano/Software.html).
moiety One of the portions into which something is divided; a component, part, or fraction. In chemistry, a specific section of a
molecule, usually complex, that has a characteristic chemical effect or property.
mole The amount of a substance that contains the same number of elements (such as atoms, molecules, or ions) as there are atoms
of carbon in 12 grams of carbon-12; one mole contains Avogadro's number of molecules (6.02×1023).
monomer A simple molecule that may combine with others to form polymers.
monosaccharide (see carbohydrate)
Messenger RNA; which serves as a template for protein synthesis. It is made as a complement to a DNA sequence and then transported from
the cell nucleus to the ribosomes.
Material safety data sheets; documentation (including data describing physical characteristics, toxicity, health effects, first aid, reactivity, storage,
disposal, protective equipment, and spill/ leak procedures) that provides workers and emergency personnel with the proper
procedures for handling or working with a particular substance.