title: 16s rRNA v4 profiing norway rat: sample W10 HT_stress
design: two-step PCR reaction with primers  F515 (5`-GTGBCAGCMGCCGCGGTAA-3') and 806R (5'-GGACTACHVGGGTWTCTAAT-3'), supplemented with a "heterogeneous spacer" of 1-5 bp and a linker sequence