CUBIC reagents were prepared as described [
12]. CUBIC-1 reagent was prepared as a mixture of 25% weight/weight (
w/w) urea (Nacalai Tesque, 35,904–45, Japan), 25% weight/volume (
w/
v) N, N, N′, N′-tetrakis (2-hydroxypropyl) ethylenediamine (Tokyo Chemical Industry, T0781, Japan), and 15% (w/v) polyethylene glycol mono-pisooctylphenyl ether (Triton X-100) (Nacalai Tesque, 25,987–85, Japan). CUBIC-2 reagent was prepared as a mixture of 50 wt% sucrose (Nacalai Tesque, 30,403–55, Japan), 25% (
w/
v) urea, 10% (w/v) 2, 20, 20′-nitrilotriethanol (Wako, 145–05605, Japan), and 0.1% volume/volume (
v/v) Triton X-100. Both reagents were prepared just prior to use. Before adding Triton X-100, all other chemicals were dissolved with a hot stirrer at 60 °C. Because water evaporation will make it difficult for highly concentrated chemicals to be dissolved, the weight of the solution was monitored frequently, and distilled water was added during a mixing step. After all chemicals except Triton X-100 were dissolved, the solution was cooled to room temperature, and finally Triton X-100 was added.