Class 1: pAAA, pCCC, pGGG, pTTT
Class 2: pAAC, pAAT, pACA, pATA, pCAC, pCCA, pCCG, pCGC, pGCG, pGGC, pGGT, pGTG, pTAT, pTGT, pTTA, pTTG
Class 3: pAAG, pAGA, pCCT, pCTC, pGAG, pGGA, pTCT, pTTC
Class 4: pACC, pATT, pCAA, pCGG, pGCC, pGTT, pTAA, pTGG
Class 5: pACG, pAGC, pAGT, pATG, pCAT, pCGT, pCTA, pCTG, pGAC, pGAT, pGCA, pGTA, pTAC, pTCA, pTCG, pTGC
Class 6: pACT, pATC, pCAG, pCGA, pGCT, pGTC, pTAG, pTGA
Class 7: pAGG, pCTT, pGAA, pTCC