This document gives an overview of the DNABarcodeCompatibility R package with a brief description of the set of tools that it contains. The package includes six main functions that are briefly described below with examples. These functions allow one to load a list of DNA barcodes (such as the Illumina TruSeq small RNA kits), to filter these barcodes according to distance and nucleotide content criteria, to generate sets of compatible barcode combinations out of the filtered barcode list, and finally to generate an optimized selection of barcode combinations for multiplex sequencing experiments. In particular, the package provides an optimizer function to favour the selection of compatible barcode combinations with least heterogeneity in the frequencies of DNA barcodes, and allows one to keep barcodes that are robust against substitution and insertion/deletion errors, thereby facilitating the demultiplexing step.
The DNABarcodeCompatibility package also contains:
experiment_design() allowing one to perform all steps
in one go.IlluminaIndexesRaw and IlluminaIndexes for running
and testing examples.The package deals with the three existing sequencing-by-synthesis chemistries from Illumina:
library("DNABarcodeCompatibility")
# This function is created for the purpose of the documentation 
export_dataset_to_file = 
    function(dataset = DNABarcodeCompatibility::IlluminaIndexesRaw) {
        if ("data.frame" %in% is(dataset)) {
            write.table(dataset,
                        textfile <- tempfile(),
                        row.names = FALSE, col.names = FALSE, quote=FALSE)
            return(textfile)
        } else print(paste("The input dataset isn't a data.frame:",
                            "NOT exported into file"))
    }
The function experiment_design() uses a Shannon-entropy maximization approach
to identify a set of compatible barcode combinations in which the frequencies
of occurrences of the various DNA barcodes are as uniform as possible.
The optimization can be performed in the contexts of single and dual barcoding.
It performs either an exhaustive or a random search of compatible DNA-barcode
combinations, depending on the size of the DNA-barcode set used, and on the
number of samples to be multiplexed.
txtfile <- export_dataset_to_file (
    dataset = DNABarcodeCompatibility::IlluminaIndexesRaw
)
experiment_design(file1=txtfile,
                    sample_number=12,
                    mplex_level=3,
                    platform=4)
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##    sample Lane    Id sequence
## 1       1    1 RPI09   GATCAG
## 2       2    1 RPI26   ATGAGC
## 3       3    1 RPI45   TCATTC
## 4       4    2 RPI16   CCGTCC
## 5       5    2 RPI21   GTTTCG
## 6       6    2 RPI29   CAACTA
## 7       7    3 RPI05   ACAGTG
## 8       8    3 RPI40   CTCAGA
## 9       9    3 RPI48   TCGGCA
## 10     10    4 RPI14   AGTTCC
## 11     11    4 RPI18   GTCCGC
## 12     12    4 RPI30   CACCGG
txtfile <- export_dataset_to_file (
    dataset = DNABarcodeCompatibility::IlluminaIndexesRaw
)
experiment_design(file1=txtfile,
                    sample_number=12,
                    mplex_level=3,
                    platform=2)
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##    sample Lane    Id sequence
## 1       1    1 RPI05   ACAGTG
## 2       2    1 RPI17   GTAGAG
## 3       3    1 RPI36   CCAACA
## 4       4    2 RPI03   TTAGGC
## 5       5    2 RPI27   ATTCCT
## 6       6    2 RPI35   CATTTT
## 7       7    3 RPI12   CTTGTA
## 8       8    3 RPI46   TCCCGA
## 9       9    3 RPI47   TCGAAG
## 10     10    4 RPI04   TGACCA
## 11     11    4 RPI33   CAGGCG
## 12     12    4 RPI45   TCATTC
txtfile <- export_dataset_to_file (
    dataset = DNABarcodeCompatibility::IlluminaIndexesRaw
)
experiment_design(file1=txtfile,
                    sample_number=12,
                    mplex_level=3,
                    platform=1)
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##    sample Lane    Id sequence
## 1       1    1 RPI07   CAGATC
## 2       2    1 RPI14   AGTTCC
## 3       3    1 RPI15   ATGTCA
## 4       4    2 RPI11   GGCTAC
## 5       5    2 RPI12   CTTGTA
## 6       6    2 RPI47   TCGAAG
## 7       7    3 RPI27   ATTCCT
## 8       8    3 RPI37   CGGAAT
## 9       9    3 RPI42   TAATCG
## 10     10    4 RPI28   CAAAAG
## 11     11    4 RPI35   CATTTT
## 12     12    4 RPI46   TCCCGA
txtfile <- export_dataset_to_file (
    dataset = DNABarcodeCompatibility::IlluminaIndexesRaw
)
experiment_design(file1=txtfile,
                sample_number=12,
                mplex_level=3,
                platform=4,
                metric = "hamming",
                d = 3)
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##    sample Lane    Id sequence
## 1       1    1 RPI01   ATCACG
## 2       2    1 RPI21   GTTTCG
## 3       3    1 RPI43   TACAGC
## 4       4    2 RPI03   TTAGGC
## 5       5    2 RPI07   CAGATC
## 6       6    2 RPI37   CGGAAT
## 7       7    3 RPI18   GTCCGC
## 8       8    3 RPI31   CACGAT
## 9       9    3 RPI33   CAGGCG
## 10     10    4 RPI12   CTTGTA
## 11     11    4 RPI30   CACCGG
## 12     12    4 RPI44   TATAAT
# Select the first half of barcodes from the dataset
txtfile1 <- export_dataset_to_file (
    DNABarcodeCompatibility::IlluminaIndexesRaw[1:24,]
)
# Select the second half of barcodes from the dataset
txtfile2 <- export_dataset_to_file (
    DNABarcodeCompatibility::IlluminaIndexesRaw[25:48,]
)
# Get compatibles combinations of least redundant barcodes
experiment_design(file1=txtfile1,
                sample_number=12,
                mplex_level=3,
                platform=4,
                file2=txtfile2)
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##       Id Lane
## 1  RPI06    1
## 2  RPI08    1
## 3  RPI21    1
## 4  RPI16    2
## 5  RPI18    2
## 6  RPI22    2
## 7  RPI05    3
## 8  RPI09    3
## 9  RPI15    3
## 10 RPI10    4
## 11 RPI11    4
## 12 RPI12    4
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##       Id Lane
## 1  RPI27    1
## 2  RPI38    1
## 3  RPI43    1
## 4  RPI33    2
## 5  RPI37    2
## 6  RPI46    2
## 7  RPI39    3
## 8  RPI45    3
## 9  RPI47    3
## 10 RPI31    4
## 11 RPI40    4
## 12 RPI44    4
##       Id Lane sequence
## 1  RPI06    1   GCCAAT
## 2  RPI08    1   ACTTGA
## 3  RPI21    1   GTTTCG
## 4  RPI16    2   CCGTCC
## 5  RPI18    2   GTCCGC
## 6  RPI22    2   CGTACG
## 7  RPI05    3   ACAGTG
## 8  RPI09    3   GATCAG
## 9  RPI15    3   ATGTCA
## 10 RPI10    4   TAGCTT
## 11 RPI11    4   GGCTAC
## 12 RPI12    4   CTTGTA
##       Id Lane sequence
## 1  RPI27    1   ATTCCT
## 2  RPI38    1   CTAGCT
## 3  RPI43    1   TACAGC
## 4  RPI33    2   CAGGCG
## 5  RPI37    2   CGGAAT
## 6  RPI46    2   TCCCGA
## 7  RPI39    3   CTATAC
## 8  RPI45    3   TCATTC
## 9  RPI47    3   TCGAAG
## 10 RPI31    4   CACGAT
## 11 RPI40    4   CTCAGA
## 12 RPI44    4   TATAAT
##    sample Lane   Id1 sequence1   Id2 sequence2
## 1       1    1 RPI06    GCCAAT RPI27    ATTCCT
## 2       2    1 RPI08    ACTTGA RPI38    CTAGCT
## 3       3    1 RPI21    GTTTCG RPI43    TACAGC
## 4       4    2 RPI16    CCGTCC RPI33    CAGGCG
## 5       5    2 RPI18    GTCCGC RPI37    CGGAAT
## 6       6    2 RPI22    CGTACG RPI46    TCCCGA
## 7       7    3 RPI05    ACAGTG RPI39    CTATAC
## 8       8    3 RPI09    GATCAG RPI45    TCATTC
## 9       9    3 RPI15    ATGTCA RPI47    TCGAAG
## 10     10    4 RPI10    TAGCTT RPI31    CACGAT
## 11     11    4 RPI11    GGCTAC RPI40    CTCAGA
## 12     12    4 RPI12    CTTGTA RPI44    TATAAT
# Select the first half of barcodes from the dataset
txtfile1 <- export_dataset_to_file (
    DNABarcodeCompatibility::IlluminaIndexesRaw[1:24,]
)
# Select the second half of barcodes from the dataset
txtfile2 <- export_dataset_to_file (
    DNABarcodeCompatibility::IlluminaIndexesRaw[25:48,]
)
# Get compatibles combinations of least redundant barcodes
experiment_design(file1=txtfile1, sample_number=12, mplex_level=3, platform=4,
                    file2=txtfile2, metric="hamming", d=3)
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##       Id Lane
## 1  RPI05    1
## 2  RPI10    1
## 3  RPI14    1
## 4  RPI01    2
## 5  RPI08    2
## 6  RPI09    2
## 7  RPI03    3
## 8  RPI07    3
## 9  RPI22    3
## 10 RPI11    4
## 11 RPI13    4
## 12 RPI23    4
## [1] "Theoretical max entropy: 2.48491"
## [1] "Entropy of the optimized set: 2.48491"
##       Id Lane
## 1  RPI29    1
## 2  RPI38    1
## 3  RPI47    1
## 4  RPI31    2
## 5  RPI40    2
## 6  RPI44    2
## 7  RPI27    3
## 8  RPI43    3
## 9  RPI48    3
## 10 RPI32    4
## 11 RPI37    4
## 12 RPI46    4
##       Id Lane sequence
## 1  RPI05    1   ACAGTG
## 2  RPI10    1   TAGCTT
## 3  RPI14    1   AGTTCC
## 4  RPI01    2   ATCACG
## 5  RPI08    2   ACTTGA
## 6  RPI09    2   GATCAG
## 7  RPI03    3   TTAGGC
## 8  RPI07    3   CAGATC
## 9  RPI22    3   CGTACG
## 10 RPI11    4   GGCTAC
## 11 RPI13    4   AGTCAA
## 12 RPI23    4   GAGTGG
##       Id Lane sequence
## 1  RPI29    1   CAACTA
## 2  RPI38    1   CTAGCT
## 3  RPI47    1   TCGAAG
## 4  RPI31    2   CACGAT
## 5  RPI40    2   CTCAGA
## 6  RPI44    2   TATAAT
## 7  RPI27    3   ATTCCT
## 8  RPI43    3   TACAGC
## 9  RPI48    3   TCGGCA
## 10 RPI32    4   CACTCA
## 11 RPI37    4   CGGAAT
## 12 RPI46    4   TCCCGA
##    sample Lane   Id1 sequence1   Id2 sequence2
## 1       1    1 RPI05    ACAGTG RPI29    CAACTA
## 2       2    1 RPI10    TAGCTT RPI38    CTAGCT
## 3       3    1 RPI14    AGTTCC RPI47    TCGAAG
## 4       4    2 RPI01    ATCACG RPI31    CACGAT
## 5       5    2 RPI08    ACTTGA RPI40    CTCAGA
## 6       6    2 RPI09    GATCAG RPI44    TATAAT
## 7       7    3 RPI03    TTAGGC RPI27    ATTCCT
## 8       8    3 RPI07    CAGATC RPI43    TACAGC
## 9       9    3 RPI22    CGTACG RPI48    TCGGCA
## 10     10    4 RPI11    GGCTAC RPI32    CACTCA
## 11     11    4 RPI13    AGTCAA RPI37    CGGAAT
## 12     12    4 RPI23    GAGTGG RPI46    TCCCGA
This section guides you through the detailed API of the package with the aim to
help you build your own workflow. The package is designed to be flexible and
should be easily adaptable to most experimental contexts, using the
experiment_design() function as a template, or building your own workflow
from scratch.
The file_loading_and_checking() function loads the file containing the DNA
barcodes set and analyzes its content. In particular, it checks that each
barcode in the set is unique and uniquely identified (removing any repetition
that occurs). It also checks the homogeneity of size of the barcodes,
calculates their GC content and detects the presence of homopolymers of
length >= 3.
file_loading_and_checking(
    file = export_dataset_to_file(
        dataset = DNABarcodeCompatibility::IlluminaIndexesRaw
    )
)
##       Id sequence GC_content homopolymer
## 1  RPI01   ATCACG      50.00       FALSE
## 2  RPI02   CGATGT      50.00       FALSE
## 3  RPI03   TTAGGC      50.00       FALSE
## 4  RPI04   TGACCA      50.00       FALSE
## 5  RPI05   ACAGTG      50.00       FALSE
## 6  RPI06   GCCAAT      50.00       FALSE
## 7  RPI07   CAGATC      50.00       FALSE
## 8  RPI08   ACTTGA      33.33       FALSE
## 9  RPI09   GATCAG      50.00       FALSE
## 10 RPI10   TAGCTT      33.33       FALSE
## 11 RPI11   GGCTAC      66.67       FALSE
## 12 RPI12   CTTGTA      33.33       FALSE
## 13 RPI13   AGTCAA      33.33       FALSE
## 14 RPI14   AGTTCC      50.00       FALSE
## 15 RPI15   ATGTCA      33.33       FALSE
## 16 RPI16   CCGTCC      83.33       FALSE
## 17 RPI17   GTAGAG      50.00       FALSE
## 18 RPI18   GTCCGC      83.33       FALSE
## 19 RPI19   GTGAAA      33.33        TRUE
## 20 RPI20   GTGGCC      83.33       FALSE
## 21 RPI21   GTTTCG      50.00        TRUE
## 22 RPI22   CGTACG      66.67       FALSE
## 23 RPI23   GAGTGG      66.67       FALSE
## 24 RPI24   GGTAGC      66.67       FALSE
## 25 RPI25   ACTGAT      33.33       FALSE
## 26 RPI26   ATGAGC      50.00       FALSE
## 27 RPI27   ATTCCT      33.33       FALSE
## 28 RPI28   CAAAAG      33.33        TRUE
## 29 RPI29   CAACTA      33.33       FALSE
## 30 RPI30   CACCGG      83.33       FALSE
## 31 RPI31   CACGAT      50.00       FALSE
## 32 RPI32   CACTCA      50.00       FALSE
## 33 RPI33   CAGGCG      83.33       FALSE
## 34 RPI34   CATGGC      66.67       FALSE
## 35 RPI35   CATTTT      16.67        TRUE
## 36 RPI36   CCAACA      50.00       FALSE
## 37 RPI37   CGGAAT      50.00       FALSE
## 38 RPI38   CTAGCT      50.00       FALSE
## 39 RPI39   CTATAC      33.33       FALSE
## 40 RPI40   CTCAGA      50.00       FALSE
## 41 RPI41   GACGAC      66.67       FALSE
## 42 RPI42   TAATCG      33.33       FALSE
## 43 RPI43   TACAGC      50.00       FALSE
## 44 RPI44   TATAAT       0.00       FALSE
## 45 RPI45   TCATTC      33.33       FALSE
## 46 RPI46   TCCCGA      66.67        TRUE
## 47 RPI47   TCGAAG      50.00       FALSE
## 48 RPI48   TCGGCA      66.67       FALSE
The total number of combinations depends on the number of available barcodes
and of the multiplex level. For 48 barcodes and a multiplex level of 3, the
total number of combinations (compatible or not) can be calculated using
choose(48,3), which gives 17296 combinations. In many
cases the total number of combinations can become much larger (even gigantic),
and one cannot perform an exhaustive search
(see get_random_combinations() below).
# Total number of combinations
choose(48,2)
## [1] 1128
# Load barcodes
barcodes <- DNABarcodeCompatibility::IlluminaIndexes
# Time for an exhaustive search
system.time(m <- get_all_combinations(index_df = barcodes,
                                    mplex_level = 2,
                                    platform = 4))
##    user  system elapsed 
##   0.346   0.018   0.365
# Each line represents a compatible combination of barcodes
head(m)
##      [,1]    [,2]   
## [1,] "RPI04" "RPI35"
## [2,] "RPI05" "RPI19"
## [3,] "RPI06" "RPI12"
## [4,] "RPI07" "RPI17"
## [5,] "RPI10" "RPI39"
## [6,] "RPI18" "RPI25"
# Total number of combinations
choose(48,3)
## [1] 17296
# Load barcodes
barcodes <- DNABarcodeCompatibility::IlluminaIndexes
# Time for an exhaustive search
system.time(m <- get_all_combinations(index_df = barcodes,
                                    mplex_level = 3,
                                    platform = 4))
##    user  system elapsed 
##   7.664   0.050   7.715
# Each line represents a compatible combination of barcodes
head(m)
##      [,1]    [,2]    [,3]   
## [1,] "RPI01" "RPI02" "RPI48"
## [2,] "RPI01" "RPI03" "RPI07"
## [3,] "RPI01" "RPI03" "RPI08"
## [4,] "RPI01" "RPI03" "RPI09"
## [5,] "RPI01" "RPI03" "RPI10"
## [6,] "RPI01" "RPI03" "RPI16"
When the total number of combinations is too high, it is recommended to pick combinations at random and then select those that are compatible.
# Total number of combinations
choose(48,3)
## [1] 17296
# Load barcodes
barcodes <- DNABarcodeCompatibility::IlluminaIndexes
# Time for a random search
system.time(m <- get_random_combinations(index_df = barcodes,
                                        mplex_level = 2,
                                        platform = 4))
##    user  system elapsed 
##   0.249   0.000   0.249
# Each line represents a compatible combination of barcodes
head(m)
##      [,1]    [,2]   
## [1,] "RPI04" "RPI35"
## [2,] "RPI06" "RPI12"
## [3,] "RPI21" "RPI29"
## [4,] "RPI22" "RPI45"
## [5,] "RPI24" "RPI31"
## [6,] "RPI26" "RPI42"
# Total number of combinations
choose(48,4)
## [1] 194580
# Load barcodes
barcodes <- DNABarcodeCompatibility::IlluminaIndexes
# Time for a random search
system.time(m <- get_random_combinations(index_df = barcodes,
                                        mplex_level = 4,
                                        platform = 4))
##    user  system elapsed 
##     1.3     0.0     1.3
# Each line represents a compatible combination of barcodes
head(m)
##      [,1]    [,2]    [,3]    [,4]   
## [1,] "RPI01" "RPI14" "RPI32" "RPI43"
## [2,] "RPI01" "RPI21" "RPI23" "RPI36"
## [3,] "RPI01" "RPI34" "RPI44" "RPI48"
## [4,] "RPI01" "RPI13" "RPI46" "RPI48"
## [5,] "RPI01" "RPI27" "RPI29" "RPI45"
## [6,] "RPI01" "RPI02" "RPI09" "RPI32"
# Total number of combinations
choose(48,6)
## [1] 12271512
# Load barcodes
barcodes <- DNABarcodeCompatibility::IlluminaIndexes
# Time for a random search
system.time(m <- get_random_combinations(index_df = barcodes,
                                        mplex_level = 6,
                                        platform = 4))
##    user  system elapsed 
##   2.312   0.045   2.358
# Each line represents a compatible combination of barcodes
head(m)
##      [,1]    [,2]    [,3]    [,4]    [,5]    [,6]   
## [1,] "RPI01" "RPI08" "RPI23" "RPI34" "RPI37" "RPI48"
## [2,] "RPI01" "RPI02" "RPI11" "RPI15" "RPI39" "RPI41"
## [3,] "RPI01" "RPI06" "RPI07" "RPI19" "RPI29" "RPI45"
## [4,] "RPI01" "RPI04" "RPI07" "RPI16" "RPI23" "RPI43"
## [5,] "RPI01" "RPI02" "RPI15" "RPI18" "RPI26" "RPI43"
## [6,] "RPI01" "RPI02" "RPI13" "RPI29" "RPI42" "RPI43"
# Load barcodes
barcodes <- DNABarcodeCompatibility::IlluminaIndexes
# Perform a random search of compatible combinations
m <- get_random_combinations(index_df = barcodes,
                            mplex_level = 3,
                            platform = 4)
# Keep barcodes that are robust against one substitution error
filtered_m <- distance_filter(index_df = barcodes,
                            combinations_m = m,
                            metric = "hamming",
                            d = 3)
# Each line represents a compatible combination of barcodes
head(filtered_m)
##      V1      V2      V3     
## [1,] "RPI01" "RPI07" "RPI41"
## [2,] "RPI01" "RPI12" "RPI42"
## [3,] "RPI01" "RPI34" "RPI48"
## [4,] "RPI01" "RPI16" "RPI46"
## [5,] "RPI01" "RPI16" "RPI43"
## [6,] "RPI01" "RPI44" "RPI45"
# Keep set of compatible barcodes that are robust against one substitution
# error
filtered_m <- distance_filter(
    index_df = DNABarcodeCompatibility::IlluminaIndexes,
    combinations_m = get_random_combinations(index_df = barcodes,
                                            mplex_level = 3,
                                            platform = 4),
    metric = "hamming", d = 3)
# Use a Shannon-entropy maximization approach to reduce barcode redundancy
df <- optimize_combinations(combination_m = filtered_m,
                            nb_lane = 12,
                            index_number = 48)
## [1] "Theoretical max entropy: 3.58352"
## [1] "Entropy of the optimized set: 3.58352"
# Each line represents a compatible combination of barcodes and each row a lane
# of the flow cell
df
##       V1      V2      V3     
##  [1,] "RPI18" "RPI23" "RPI32"
##  [2,] "RPI13" "RPI20" "RPI30"
##  [3,] "RPI01" "RPI35" "RPI48"
##  [4,] "RPI17" "RPI24" "RPI29"
##  [5,] "RPI05" "RPI19" "RPI27"
##  [6,] "RPI04" "RPI07" "RPI31"
##  [7,] "RPI16" "RPI37" "RPI45"
##  [8,] "RPI14" "RPI21" "RPI46"
##  [9,] "RPI10" "RPI25" "RPI39"
## [10,] "RPI03" "RPI22" "RPI28"
## [11,] "RPI34" "RPI38" "RPI43"
## [12,] "RPI02" "RPI26" "RPI42"
# Keep set of compatible barcodes that are robust against multiple substitution
# and insertion/deletion errors
filtered_m <- distance_filter(
    index_df = DNABarcodeCompatibility::IlluminaIndexes,
    combinations_m = get_random_combinations(index_df = barcodes,
                                            mplex_level = 3,
                                            platform = 4),
    metric = "seqlev", d = 4)
# Use a Shannon-entropy maximization approach to reduce barcode redundancy
df <- optimize_combinations(combination_m = filtered_m,
                            nb_lane = 12,
                            index_number = 48)
## [1] "Theoretical max entropy: 3.58352"
## [1] "Entropy of the optimized set: 2.8177"
# Each line represents a compatible combination of barcodes and each row a
# lane of the flow cell
df
##       V1      V2      V3     
##  [1,] "RPI12" "RPI28" "RPI48"
##  [2,] "RPI15" "RPI28" "RPI46"
##  [3,] "RPI24" "RPI25" "RPI28"
##  [4,] "RPI03" "RPI27" "RPI41"
##  [5,] "RPI14" "RPI30" "RPI44"
##  [6,] "RPI03" "RPI27" "RPI41"
##  [7,] "RPI14" "RPI30" "RPI44"
##  [8,] "RPI21" "RPI37" "RPI43"
##  [9,] "RPI03" "RPI27" "RPI41"
## [10,] "RPI14" "RPI19" "RPI30"
## [11,] "RPI08" "RPI18" "RPI28"
## [12,] "RPI21" "RPI37" "RPI43"