title: Multichannel photometer-nephelometer.
abstract: We describe an instrument for monitoring either transmitted or scattered light intensity, or both, simultaneously on up to eight channels. The use of a laser light source (at 632.8-nm wavelength) provides high accuracy and dynamic range: optical density can be measured from 0.0004 up to 6, and a scattered light fraction down to 10(-6) can be resolved. Built-in thermostat and magnetic stirrers allow precise monitoring of aqueous microbial growth over a practical range of 4 orders of magnitude of cell concentration.
mesh_terms: D004926:Escherichia coli / Q000254:growth & development; D007834:Lasers; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation*; D010400:Penicillin G / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000254:growth & development; D012542:Scattering, Radiation
chemical_list: D010400:Penicillin G