The molecular size of γ-PGA was estimated by agarose gel electrophoresis. Portions
(10 µl) of pure γ-PGA were resolved by electrophoresis at 6 V/cm for 30 min on 1.0%
1334 Appl Biochem Biotechnol (2010) 160:1332–1340
agarose gels using TAE running buffer [40 mmol/l Tris-hydroxylaminomethane, 1 mmol/
l EDTA, 0.14% (v/v) acetic acid]. The γ-PGA samples on the gel were visualized by staining
with methylene blue [0.23% (w/v) methylene blue, 23% (v/v) ethanol, 0.008% (w/v) KOH] for
10 min, followed by destaining with water.