title: Measurement of in vitro microtubule polymerization by turbidity and fluorescence.
abstract: Tubulin polymerization may be conveniently monitored by the increase in turbidity (optical density, or OD) or by the increase in fluorescence intensity of diamidino-phenylindole. The resulting data can be a quantitative measure of microtubule (MT) assembly, but some care is needed in interpretation, especially of OD data. Buffer formulations used for the assembly reaction significantly influence the polymerization, both by altering the critical concentration for polymerization and by altering the exact polymer produced-for example, by increasing the production of sheet polymers in addition to MT. Both the turbidity and the fluorescence methods are useful for demonstrating the effect of MT-stabilizing or -destabilizing additives.
authors: Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA.
authors: Matthew
authors: M
authors: Mirigian
authors: Kamalika
authors: K
authors: Mukherjee
authors: Susan L
authors: SL
authors: Bane
authors: Dan L
authors: DL
authors: Sackett
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology; D002417:Cattle; D005453:Fluorescence; D005456:Fluorescent Dyes; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism*; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D058105:Polymerization / Q000187:drug effects*; D051381:Rats; D013053:Spectrophotometry / Q000379:methods; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D014404:Tubulin
keywords: Critical concentration; Fluorescence; Microtubules; Optical density; Polymerization; Tubulin; Turbidity; Turbidity coefficient