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Correction: Sodium boric acid: a Tris-free, cooler conductive medium for DNA electrophoresis

An error appeared in Brody and Kern (BioTechniques 36:214-216; February 2004) in the article entitled “Sodium boric acid: a Tris-free, cooler conductive medium for DNA electrophoresis.” The authors referred to an optional 0.1% ethidium bromide in DNA gels; they intended to refer not to units of gram percent but to a dilution of a laboratory stock solution, which produced a final gel concentration of 0.2 µg/mL (micrograms per milliliter) of sodium ethidium bromide.

The authors regret this oversight. The PDF version of the article, available at http://www.BioTechniques.com, has been corrected.

Correction: Ultra-fast high-resolution agarose electrophoresis of DNA and RNA using low-molarity conductive media

Three errors appeared in Brody et al. (BioTechniques 37:598-602; October 2004) in the article entitled “Ultra-fast high-resolution agarose electrophoresis of DNA and RNA using low-molarity conductive media.” The authors referred to an optional 0.1% ethidium bromide in DNA gels; they intended to refer not to units of gram percent but to a dilution of a laboratory stock solution, which produced a final gel concentration of 0.2 µg/mL (micrograms per milliliter) of sodium ethidium bromide. Additionally, the RNA loading medium was incorrectly given as containing 22% formaldehyde and 20% formamide; the authors in fact had used standard denaturant quantities of 7.4% formaldehyde and 57% deionized formamide in the loading medium, which was otherwise as stated. Finally, in describing RNA gels containing 0.67% (0.22 M) formaldehyde rather than the standardly used 6.7% (2.2 M) formaldehyde, the authors neglected to provide a literature reference. The appropriate citation is as follows: Davis, L., M. Kuehl, and J. Battey. 1994. Formaldehyde agarose gel electrophoresis and RNA (Northern) blots, p. 350-354. In Basic Methods in Molecular Biology, 2nd ed. Appleton & Lange, Norwalk, CT. The authors note that the lower formaldehyde content appeared to suffice and had the advantage of permitting gel formation outside of a fume hood; they have not explored lower formaldehyde concentrations, nor the variables that might favor a particular formaldehyde content.

The authors regret these oversights and any confusion that may have resulted. The PDF version of the article, available at http://www.BioTechniques.com, has been corrected.