Phenol

S. aureus (CICC 23926), E. coli (CICC 10899) and C. albicans (CICC 32380) were purchased from China Center of Industrial Culture Collection (Beijing, China). Catalase, methylglyoxal (HPLC grade), gallic acid, quercetin, and DPPH were purchased from Sigma-Aldrich (St. Louis, MO, USA). H₂O₂ quantitative analysis kit (water-compatible), LB broth, and phenol were purchased from Sangon Biotech (Shanghai, China). Nutrient agar was purchased from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China).

Total DNA was isolated by standard phenol (Sangon Biotech, Shanghai, China) -chloroform (Lingfeng Chemical Reagent Co., Ltd., Shanghai, China) extraction. Fragments of the mitochondrial Nd2 gene and GAPDH gene were amplified in duplicate by qRT-PCR. Primers are shown in Table 1. MtDNA copy number was expressed as the mtDNA-to-nuclear-DNA ratio (Nd2 mtDNA/GAPDH DNA) [55 (link)].

Antennae from twenty moths were homogenized in 1 mL Trizol (Invitrogen, Carlsbad, California, USA) and RNA was extracted following the manufacturer’s instructions. The RNA was treated with RQ1 DNase (Promega, Madison, USA) to avoid the risk of genomic DNA contamination, followed by purification with phenol, chloroform and isoamyl alcohol (Sangon, Shanghai, China). The quality of RNA was evaluated by agarose gel electrophoresis and its concentration measured with Nanodrop 2000 (NanoDrop Technologies, Wilmington, DE, USA). The first strand cDNA was synthesized from 2 μg RNA utilizing cDNA synthesis with SuperScript® III RT kit (Invitrogen).