Microbial mining
The use of microorganisms to remove minerals from rocks. There are two main areas in microbial mining: leaching, which involves use of bacteria to solubilise metals in ores, and purification, which involves use of microorganism to separate and concentrate metals from dilute solutions.

Microbodies
Cytoplasmic membrane-bounded vesicles that contain peroxide-forming and peroxide-catabolising enzymes such as lysosomes, glyoxysomes and peroxisomes.

Microcapsule
A very thin version of the capsule surrounding a bacterial cell wall. It is a gel like matrix made of polysaccharides that protects the bacterial cell from phagocytosis.

Microcarriers
Small particles used as a support material for cells, especially mammalian cells, which are too fragile to be pumped and stirred as bacterial cells are in a large-scale culture.

Microcells
Cell-like particles containing a single chromosome within a small nucleus surrounded by minimal cytoplasm and a cell membrane. These are generated by prolonged inhibition of mitosis followed by centrifugation.

Micrococcal nuclease
An endonuclease produced by Staphylococcus aureus that cleaves the covalent backbone of DNA strands. It is used for mapping protein binding sites of DNA.

Microcurie (mCi)
Ci × 10^-6

Microdroplet array
A technique developed by Kao and Konstable to evaluate large numbers of media modifications, using small quantities of medium into which are placed small numbers of cells. Droplets of liquid arranged on the lid of a Petri dish, are inverted over the bottom half of the dish that contains a solution with a lower osmotic pressure and the dish is sealed. The cells or protoplasts form a monolayer at the droplet meniscus  and can be readily examined. Also termed multiple drop array (MDA); hanging droplet technique.

Microelectrode, micropipette
A piece of fine glass tubing that is drawn into a fine tip. It is used to penetrate a cell in order to study its physiology or to inject molecules or electric current.

Microelement
An element required in minute amounts.

Microencapsulation
The process of enclosing a substance in extremely small sealed capsules from which material is released by heat, or other means.

Microenvironment
The environment that is sufficiently close to the surface of a living or nonliving object so that it is influenced by it.

Microfibrils
A bundle of fine cellulose fibers that form the plant cell wall. These are extremely small fibres visible only at the high magnification of the electron microscope.

Microfilaments
Thin filaments made of actin present in the cytoplasm of eukaryotic cells. They play a role in structure and movement.

Microfluidics
The miniaturization of chemical reaction or pharmacological assays into microscopic tubes or vessels to enhance their throughput, by placing them side by-side in an array.

Microglobulin
A short peptide noncovalently bound to class l major histocompatibility complex glycoprotein.