FastQCFastQC Report
Thu 25 Nov 2021
HVTN5DSX2_l03_n02_GDO-CPAcore_K562-L2.fastq.gz

Summary

[OK]Basic Statistics

MeasureValue
FilenameHVTN5DSX2_l03_n02_GDO-CPAcore_K562-L2.fastq.gz
File typeConventional base calls
EncodingSanger / Illumina 1.9
Total Sequences63720535
Sequences flagged as poor quality0
Sequence length101
%GC48

[OK]Per base sequence quality

Per base quality graph

[WARN]Per tile sequence quality

Per tile quality graph

[OK]Per sequence quality scores

Per Sequence quality graph

[FAIL]Per base sequence content

Per base sequence content

[FAIL]Per sequence GC content

Per sequence GC content graph

[OK]Per base N content

N content graph

[OK]Sequence Length Distribution

Sequence length distribution

[FAIL]Sequence Duplication Levels

Duplication level graph

[FAIL]Overrepresented sequences

SequenceCountPercentagePossible Source
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCTCCCGCTTCACGCGGCG27050694.245207608504856Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGGACTTCAGTCGTGCGTG26051324.088371197762228Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCGGTGAGAGACCCGGCAA17043122.674666808745407Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCAGGCTGCGAAGCCCGAAA16377762.5702483508652274Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGGCTCTGCTGTCGGCGGA15260072.3948433577966663Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCTCGAAGAATCCGCTATG12244971.9216677951621088Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCCGCAGCCCCAGCAGGAG11360351.782839707795925Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTAGTGAAAACACCACAAAA10542191.6544415391364808Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCCTCGCCGTGCGTCACAG10231471.6056786089445108Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCGCCATATTCCCGGTAAC10081571.582154010477156Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCAGTGGTAGCGCTCGTCTG10075741.581239077794937Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCCTCTGTGACGCACGGCG9779521.5347517091625174Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTTCCCGGTAACGGGGGCGC9161361.437740596496875Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGGAGAAGCGCTTAAAGCG8344091.3094821002366035Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCCGCTGCCGCCATCCCGC8071611.266720375150648Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGAATCGTAACCTCGCCAT8029681.2601400788615476Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGGTTTAAATTCTGCACGG7967911.2504461866178618Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGACTGTGAGAGACCCAGCGG7764031.2184502217377804Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGCCAGTGGTAGCGCTCGT7653511.2011057345956055Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGACAGCGCTCTCGTGTACTA7473691.1728856325515786Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGACTCCGCTGGCTCGGTCCG7164421.1243502585155634Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCAATTCTCACTCACGACC7048781.1062022627399473Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCTTCCGGGTGTCTTTGAC6578381.0323799070425255Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGGAACGCCGCCGCCGCCG6537961.0260365830261784Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGAACCGGACCAGCTGGTA6414361.0066393824220088Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGCCGCGCAGCAGCCCGGG5985800.9393831988384905Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTGGGAAGCGGCGCCATAT5724930.8984434923529754Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCGCCATCCCGCTGGAGAG5485300.8608370912140019Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGAAAGCTCACAAGAACTG5131210.8052678779297757Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCGCTCGGCGAAGACAGAG4714010.7397944791267054Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGGCCGTGGTGAGAGCGTG4614640.724199820356185Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGACTGCCAGGGGTGCGAGAA4576680.7182425571285614Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGGCGGCCGTGGTGAGAGC4427660.6948560617075797Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAAGATGCAAGAGGTCATTG4232180.664178353179238Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGCACTAACCGCCGGGGAG4077160.6398502460784424Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCACTCTCAGCACTAACCGC4073490.6392742936009561Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCAGTGATCGATCCATTGCC4020800.631005373699389Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGAGCCCCCGAGCGGCAGG3670200.5759838645422547Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCGAAGCAGGGAGCGACCC3380040.5304475237064472Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGTAGAGAACGATCCACCG3367670.5285062342932306Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGACGGAGATCACCCGCGAGA3224130.5059797442064792Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGATGCAAGAGGTCATTGC3175590.49836210571678347Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCACTAACCGCCGGGGAGAA3040220.4771177768673788Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTCCCGCTTCACGCGGCGC2991690.46950170773048283Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTCTAGGACACTGACTCCG2895820.45445632243985395Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTAGAGAACGATCCACCGCG2890170.4535696381080291Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCTCCTCTGTCTTCGCCGA2739930.42999168164548524Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGGACGTGAGCGATAATGG2703470.42426982133781516Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGGGAGCTGCCCCTAACCG2696440.4231665663196331Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGACCTGGGCTCTCACGTACC2644010.41493844959085796Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAAGACAGAGGAGGAAGCGC2601000.40818866319939096Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGTTTGGCGGTGAGAGACC2591480.4066946393340859Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCAGCTGGTACTGGGACAC2571600.403574765968302Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAAGCCCGAAAGCGGCGGAG2547850.3998475530690381Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGCGGGGCTCGGGCCTATT2476980.3887255497776345Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGGCCGAGGCTGAAGGAAG2419620.37972374211861215Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTTGTTGCGTATACGAGAC2356510.369819556599768Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGTGGTGAGAGCGTGGGGA2298280.36068121524717267Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGAAGCCCGAAAGCGGCGG2263480.35521986750425116Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAATTTAAACCAAACTACAA2196370.34468794086553106Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTACCGACTGACAGACTGCC2168150.34025922726480556Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGTGGCCGCGGCCAGGGAG2151820.3376964741429117Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCAGCTTCCGCAGCCCCAGC2114030.3317658899128829Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGAGCGGCGGGGTAAGATG2113530.3316874222728984Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGAGCGATAATGGCGGATA2076190.32582745891885556Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGATAGGTTTGGTCCTAGCCTT2053060.32219754589317245Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTATTTATGACAATACAGC2050710.32182874798524524Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGCGATAATGGCGGATATG1960920.307737529196828Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCCAATAGGCCCGAGCCCC1957440.30719139442253585Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGGCGGAGCTGGGTGAGTT1888650.29639581651346775Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTGCGAAGCCCGAAAGCGG1862650.2923154992342735Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGGGGGCTCTCACCGAGCG1862260.2922542944750856Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGGTGGGATTGGTGTTGGG1819890.28560494666279873Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCCCGGCCGGCGAGCGGGC1809790.28401990033511176Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAACTACAAGTAAAAGTATC1785550.28021578914866296Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCCTCTCTCCAGCGGGATG1657110.26005902178944357Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTGCGGGCGGTCGGGGCTC1620990.25439051947696295Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCGGGTGGCCATCTTGTGG1590300.24957417573471408Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCGGACGAGCGCCCCACTG1549090.24310687284719124Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCCCGCTCGGCGAAGACAG1539840.24165522150747792Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTCCCGCTTCACGCGGCGG1511150.23715274832516708Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGTCGTGCGTGAGGGCTGC1503810.23600084337019456Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAAAGTGTGAGGGCGAAGCG1497200.2349635011695994Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCGAGAGCAGCGGGGAGCC1470850.230828256542416Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCGTGCGTCACAGAGGCCG1420010.22284966690879165Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGCGCCATGTTAGGACGAAG1320730.2072691323134685Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTAAGGCCCGCGTACGAGCT1301260.2042136024124719Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAAGCGGCGCCATATTGGCG1262420.1981182361384756Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCCGAGCGGCGGGGTAAGA1255960.19710443422987584Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTGGTGAGAGCGTGGGGAAG1220550.19154735596617323Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGACCGCCGAGACCGCGTCCG1215540.1907611102135285Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCAGTCGGAGGAACAGACGG1203760.18891241261549357Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCAGCCACCGGTAAATAAAA1163350.18257065795194594Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCGCTGCCGCCATCCCGCG1136650.17838048597677342Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCGCCTCCGGACCGAGCCA1116770.17526061261098955Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCGGCTCCAACTGCCAGGT1047620.1644085380011326Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGATCAGAGTCACGCCCTT1033060.16212356032478384Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCGCAGTCATTCGATAGGAA936200.14692280910698569Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGAGGACTTCAGTCGTGCGTGG920210.14441341398028124Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTCGGGGGCTCTCACCGAG907820.14246898586146522Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGGTAGTGAAAACACCACAAA902740.14167175463922266Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGCTCGAGACTCCAATCCC894090.14031426446749073Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGATAACCGCTTCCCGCAC883440.13864290373582078Clontech SMARTer II A Oligonucleotide (100% over 25bp)
GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG877540.13771698558400366No Hit
AAGCAGTGGTATCAACGCAGAGTACATGGGGAAAACCCTGTCAAAGACAC836840.13132971968926502Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCTCTGTGACGCACGGCGG830640.13035672095345716Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTCCTGCAGGTCTGCCCGCC820320.12873714886417698Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGAAAAAAAAAAAAAAAAAAAA811040.12728078946606458Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCCGCTTCACGCGGCGCGGG791210.12416876286427915Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGATCAGGCCTTGTCCGTGAT785310.12324284471246201Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAAGACAGAGGAGGACGCGC762210.11961763974517792Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGACCGACCCGCCCGCCCG745180.11694503192730571Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGAGGACTTCAGTCGTGCGTGA741720.11640203585861293Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGAGCGGGATACCAAGAGAAC711310.11162963399475537Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGAGGAGAAGCGCTTAAAGCGG680540.106800735430109Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTTTGTCGCGGCGGCGAAGG678610.1064978503397688Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGCTGCTGTTGGTTCGTCGCG677720.10635817794059639Clontech SMARTer II A Oligonucleotide (100% over 25bp)
AAGCAGTGGTATCAACGCAGAGTACATGGGGTAAATTGGAAGCACAGCCA673770.1057382835847188Clontech SMARTer II A Oligonucleotide (100% over 25bp)

[OK]Adapter Content

Adapter graph