staphylococcus aureus strain typing by single-molecule...
TRANSCRIPT
White, E.J., et al. 1
Supplemental Data
Staphylococcus aureus Strain Typing by Single-Molecule DNA Mapping in Fluidic
Microchips with Fluorescent Tags
Eric J. White, Sergey V. Fridrikh, Nirupama Chennagiri, Douglas B. Cameron, Gregory P.
Gauvin, Rudolf Gilmanshin
Mini-Reactor System for Preparation of Tagged DNA Samples
The automated mini-reactor (MR) system has been designed to extract, purify, and process large
fragments of bacterial genomic DNA (1). Injected cells are collected on the ultrafiltration
membrane within the MR and are subjected to a series of consecutive enzymatic and
hybridization reactions at various temperatures as well as to selective wash and buffer exchange
steps. Cells and subsequently DNA are held on the membrane throughout the procedure by a
small flow through the membrane, while cell debris and byproducts of the reactions are
selectively removed from the MR. The system can produce long DNA fragments (up to 0.5 Mb)
of bacterial genome restriction digest and perform tagging of DNA with fluorescent sequence-
specific probes. The MR produces DNA of high purity, floating free in solution, ready for direct
linear analysis (DLA). Except for injection of the cells and reagents, all other steps of the
protocol are automated. Therefore, the processing excludes operator-related variations and is
very reproducible. The quality of MR-produced DNA is equal or superior to that of agarose plug
preparations.
White, E.J., et al. 2
The MR function is based on three concepts. First, from the moment DNA molecules are
released from cells and until specifically digested down to submegabase fragments, they remain
immobilized on the membrane and encounter only low flow rates. This approach protects DNA
from damage. Second, introduction of reagents into the MR occurs by forced penetration through
the sample layer in an injection mode. This approach eliminates both reliance on diffusion and
the need for mixing. The former accelerates processing, the latter preserves DNA. Third, rapid
and efficient buffer exchange and removal of reaction byproducts can be achieved with a
selective wash mode. In this mode, even particles too large to pass through the membrane can
still be efficiently removed from the MR by tangential flow along the membrane. This permits,
for example, injection of cells in broth for processing directly from cultures.
DNA isolation and processing is performed within a conical reaction chamber. In every
mode, except for elution mode, all sample solutions, reagents, and buffers are injected through
the injection inlet on top of the chamber. The inlet flow can leave the chamber either through the
membrane, or through the side outlets, or both. All flows are carefully controlled. Samples and
reagents are introduced through a manual injection valve.
The sample preparation protocol consists of sequential, computer-controlled, steps. Each
step belongs to one of 5 modes: injection, selective wash, elution, backside frit wash, or line
priming. Every mode defines the directions of the flows through the chamber. Each step has
variables such as: solution to be used, volume to be delivered, flow rates, chamber temperature,
and incubation time.
In injection mode, the flow controller valve is closed and the bottom outlet is opened;
therefore, only normal flow (through the membrane) exits the reactor.
White, E.J., et al. 3
In selective wash mode, both the flow controller valve and the bottom outlet are open. A
portion of the inlet flow exits through the side outlets and the flow controller valve. The
remaining portion of the flow passes through the membrane into the bottom cavity.
Incubation steps are usually performed in the absence of flow by closing all inlets and
outlets of the MR.
Elution of the DNA sample from the chamber is performed by reversing the flow through
the membrane. The flow lifts the DNA sample from the membrane and carries it out through the
injection line for fraction collection.
In this work, we used the MR system to produce samples of tagged genomic DNA from
Staphylococcus aureus. The sample preparation protocol is presented in the Supplemental Data
Table 4. The complete procedure took approximately 5 hours. Cells or reagents were injected
manually in 100 µL aliquots into the injection loop and pushed into the reaction chamber by the
volume of buffer indicated in Supplemental Data Table 4. We typically injected 108 cells for
each preparation.
Direct Linear Analysis
SYSTEM AND MEASUREMENTS
DLA technology (2) employed both hybridization of long DNA molecules with fluorescent
sequence-specific tags, such as bisPNA, and non-specific staining with another color fluorescent
dye, such as intercalator. The stained and tagged DNA molecules were directly introduced into a
microfluidic chip, where they were uncoiled and conveyed in this stretched conformation to the
detection zone for single-molecule mapping. There were two displaced spots at which the
fluorescence of stained DNA was measured. Using the known distance between the spots and the
delay between the detections at the spots, the velocity and length of each DNA molecule were
White, E.J., et al. 4
determined. Simultaneously, using detection of different color fluorescence, the positions of the
hybridized tags along the DNA molecule were determined. Measurements were performed as
described previously (2, 3) at a linear flow rate of ~12 µm/ms, and data was recorded at 30 kHz.
The first spot for detection of intercalated DNA was 40 µm apart from the funnel. A new color
scheme was used with DNA intercalated by POPO-1, which was excited with blue light at 445
nm. Emission from the ATTO550 (bisPNA tag) fluorophore was excited by green laser light at
532 nm. The new optical components required for POPO-1 detection are presented in (1). Other
components of the optical system were the same as published previously (3).
MICROFLUIDIC CHIP
The fused silica chip used in this study was similar to the microfluidic device described
earlier (4). It also employed a four-port design with hydrodynamic flow focusing. However, its
geometry had been modified to be compatible with longer DNA. The chip is 1 µm deep with a 5
µm wide interrogation channel. The taper shape has a profile width described by W(x) ~
Wi/(1+(x/a)) where W is the width, x is the coordinate along the flow direction, and a = 4.040816
(all measured in microns). The taper length is 198 µm and the width of the channel before the
taper, Wi, is 250 µm. The injection port and sheathing buffer pressures were adjusted to obtain
the focusing ratio of about 20 (the width of the sample flow is 1/20 of the width of the
interrogation channel. The chips were manufactured by Micralyne, Inc. (Edmonton, Alberta,
Canada).
Data Analysis
SINGLE-MOLECULE MAPS
Using an in-house software package, single molecule DNA traces were located in the data stream
by identifying correlated signals between the two laser light spots, which excite intercalator
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fluorescence. The length, velocity, average intensity, and tag signal of each molecule were
extracted as described previously (2, 5).
GENERATION OF THEORETICAL MAPS
To assess the accuracy of maps obtained with DLA, we generated theoretical maps of restriction
fragments of the strains with known genomic sequences. Using the known cognate sequence of
the restriction enzyme and complementary sequence of the bisPNA tag, we determined the
expected restriction fragments, their lengths, and the positions of the hybridized tags. The
hybridization sites with both exactly and partially matching sequences were considered as
possible tag sites. Of the latter, only the sites with a single mismatch at one of the termini (single
end mismatch sites, SEMM) were included (2, 3). All hybridization sites were assigned binding
probabilities, differing for matching and SEMM sites, which defined the intensities of the peaks
in the averaged theoretical fragment map. The degrees of tagging, which varied slightly from
experiment to experiment, could be adjusted to fit the experimental traces.
IDENTIFICATION OF MAPS OF ALL LONG FRAGMENTS
Data analysis was a multistep process, starting with interpolation and filtering of single-molecule
traces (Supplemental Data Fig. 6). Interpolation involved transforming the data associated with
each molecule from uniform time intervals (bins), which varied in number depending on the
length and velocity of each molecule, onto a regular grid of 200 intervals for every molecule.
This facilitated the comparison of molecules in subsequent steps.
Filtering involved excluding molecules that were unlikely to be identified due to hairpin
conformations, overlapping, or spurious contaminants with bright fluorescence detected
simultaneously with the DNA molecules. Folded and overlapped molecules were readily
identified by uneven intensity profile of intercalator fluorescence. They were excluded if the
White, E.J., et al. 6
intercalator fluorescence intensity surpassed a threshold of approximately twice the median value
for that molecule over a fixed number of consecutive bins. Contaminants were identified by
anomalous brightness in the tag detection channel, and DNA molecules were excluded if the
number of photons in any bin detected in that channel exceeded the threshold of 200 photons,
which was about 5-fold stronger than the expected maximal peak intensity. Both filters combined
excluded 25% to 75% of single molecule traces in different experiments.
Next, we calibrated the conversion between observed geometric DNA length in microns
and genomic length in kilobases. The conversion depended on the degree of intercalation, which
varied between experiments. We added a length standard to each sample, a 126 kb recombinant
DNA fragment, which was developed in our laboratory and produced in large quantities. This
fragment was intercalated but untagged to be readily identifiable by its low average intensity in
the tag detection channel. By testing E.coli samples whose fragments were of known length (data
not shown), we found that the conversion was slightly non-linear and a small fixed quadratic
term was included in the calibration. The final length accuracy was ±2-3%.
The molecules passing filtration were then grouped into clusters to identify average
restriction maps. The software was written to perform k-means clustering over several stages
(Supplemental Data Fig. 6). Initially we employed a rank-based metric to evaluate the similarity
of each pair of traces expressed as a trace-to-trace distance. The trace with the closest n nearest
neighbors on average was selected as a center of a potential cluster with the parameter n an
adjustable parameter. This trace and its n nearest neighbors were declared a cluster. This
procedure was repeated until all traces were divided into preliminary clusters of n+1 traces.
Preliminary clusters with similar averages were merged. Averages of the resulting clusters were
used as seed templates for clustering in a second clustering stage. For this stage, trace-to-seed
White, E.J., et al. 7
template distances were defined as 1 – c(i,j), where c(i,j) is the correlation coefficient of the i-th
trace and j-th seed template The final clustering step employed a probability distance metric
based on intensity probability distributions generated for all bins of all clusters. As a result of
this clustering, we obtained a set of average trace maps for each restriction fragment of a
digested microorganism.
In some cases, the resulting trace average included non-linear distortions of position
along the DNA as a result of molecule acceleration in the stretching funnel during detection. This
occurred if the length of a DNA fragment exceeded the distance between the stretching funnel
and the excitation light spot. We developed and applied a numerical routine to correct for the
dominant harmonic term of this distortion by optimizing the similarity between head-first and
inverted tail-first pairs of the same fragment.
SAMPLE SIMILARITY INDEX
To quantify the similarity of samples, the average trace from each fragment in one sample was
compared to the average trace of each fragment in the other sample. The minimum of Spearman
and Pearson correlation coefficients between average traces was used to quantify the similarity
of fragments. The current algorithm was capable of comparing either two fragments as a whole
or one whole fragment as subset of another fragment (Supplemental Data Fig. 7). Two fragments
were considered matching if the correlation coefficient between them was greater than an
empirically determined threshold of 0.7.
To determine the threshold, we compared all fragments and plotted a histogram of the
correlation coefficients. The histogram exhibited two peaks at low and high correlation
coefficients corresponding to pairs of different and similar fragments, respectively. The peaks
were separated by a distinct valley between correlation coefficients of 0.65 and 0.75. We picked
White, E.J., et al. 8
a value of 0.7 around the center of the valley as the threshold. However, the results were not
sensitive to the exact value of the threshold until it was in the range between 0.65 and 0.75.
To quantify the similarity between two samples, an index called the sample similarity
index (SSI) was defined as the ratio of total length of matching traces to the average total length
of the traces from the two samples. Thus two strains sharing all optical traces have an SSI of 1.0,
while two strains sharing no optical traces have an SSI of 0. We used (1 – SSI) as the “distance”
between the two samples. A matrix of the distances between all pairs of the measured samples
was generated (Supplemental Data Fig. 8), and this matrix was used to generate a phylogenetic
tree using the Fitch–Margoliash least-squares method (6).
NEIGHBORHOOD-BASED RESISTANCE PREDICTION
The SSI's between a test sample and known samples can be used to predict properties such as
antibiotic resistance. We classify a sample as resistant to an antibiotic if a fraction f of samples
within a distance d is resistant to the antibiotic. Parameters f and d are thresholds that define the
'neighborhood'. These parameters can be varied to operate at different true positive (sensitivity)
and false positive (1 – specificity) rates. To calculate these rates for a particular value of f and d
based on a set of known samples, we predict the antibiotic resistance of each sample as if it were
an unknown. For each (f,d) pair, the true positive rate is the fraction of antibiotic-sensitive
samples correctly predicted to be antibiotic-sensitive, and the false positive rate is the fraction of
antibiotic-resistant samples incorrectly predicted to be sensitive. The receiver operating
characteristic (ROC) shows the optimal rates that can be obtained by varying these thresholds
(Supplemental Data Fig. 5). The classifier can attain approximately 95% true positive rate with
5% false positive rate for the identification of oxacillin resistance in the small sample size of this
study.
White, E.J., et al. 9
References
1. Mollova ET, Patil VA, Protozanova E, Zhang M, Gilmanshin R. An automated sample preparation system with mini-reactor to isolate and process submegabase fragments of bacterial DNA. Analytical Biochemistry 2009;391:135-43.
2. Phillips KM, Larson JW, Yantz GR, D'Antoni CM, Gallo MV, Gillis KA, et al. Application of single molecule technology to rapidly map long DNA and study the conformation of stretched DNA. Nucleic Acids Res 2005;33:5829-37.
3. Chan EY, Goncalves NM, Haeusler RA, Hatch AJ, Larson JW, Maletta AM, et al. DNA mapping using microfluidic stretching and single-molecule detection of fluorescent site-specific tags. Genome Res 2004;14:1137-46.
4. Krogmeier JR, Schaefer I, Seward G, Yantz GR, Larson JW. An integrated optics microfluidic device for detection single DNA molecules. Lab on a Chip 2007;7:1767-74.
5. Larson JW, Yantz GR, Zhong Q, Charnas R, D'Antoni CM, Gallo MV, et al. Single DNA molecule stretching in sudden mixed shear and elongational microflows. Lab Chip 2006;6:1187-99.
6. Fitch WM, Margoliash E. Construction of phylogenetic trees. Science 1967;155:279-84.
White, E.J., et al. 10
Supplemental Data Figure Legends
Supplemental Data Figure 1. PFGE analysis of restriction digests of control S. aureus strains
with SmaI (A, B) and SanDI (C, D) restriction endonucleases. Strain NCTC8325 (NRS77) is
used as the length standard and indicated by an asterisk. Bands corresponding to the fragments
differing from those expected from published genomic sequences are circled.
Supplemental Data Figure 2. Comparison of theoretical maps from genomic sequences (red)
with experimental maps (head- and tail-first orientations are in green and blue, respectively) for
the 193 kb DNA fragments of S. aureus strains Mu50 (A) and Mu3 (B). Instead of a 153 kb long
fragment with the same map for both Mu50 and Mu3 strains expected from their published
sequences, we have detected the same 193 kb fragment for both of them. The theoretical map
overlaps nicely with a part of it.
Supplemental Data Figure 3. Reproducibility of DLA measurements. Maps of SanDI
restriction fragments of S. aureus strain NCTC8325 were measured 7 times on different days by
different operators on different devices. Raw traces for all 9 fragments detected within 100-250
kb range (108, 109, 116, 134, two 150, 160, 180, and 242 kb long fragments) are presented
without normalization. See Fig. 4 for examples of the traces normalized to their maximal
intensity.
Supplemental Data Figure 4. Pulsed field electrophoresis gels of all Mount Auburn Hospital
isolates measured in this study. Genomic DNA was digested with SmaI restriction endonuclease.
Supplemental Data Figure 5. Receiver operator characteristic (ROC) for the prediction of
methicillin (oxacillin) resistance of Mount Auburn Hospital samples. The curve indicates that we
can achieve approximately 95% true positive rate with 5% false positive rate (intersection of blue
dotted lines).
White, E.J., et al. 11
Supplemental Data Figure 6. Flow chart of the identification and extraction of the maps of the
long restriction fragments of the sample DNA. See the Supplemental Data text for details.
Supplemental Data Figure 7. Comparison of two hypothetical samples. Suppose that for two
measured samples of different bacteria, we detected 3 and 4 maps of restriction fragments,
respectively (A). The current algorithm identifies matching sections of the maps when either two
fragments from the different samples match completely or one fragment of one sample matches
as a whole a section of a fragment from another sample (B). The latter case is illustrated with the
experimental data (C). One of the fragment maps of E. coli strain K12 MG1655 strain (blue)
matches a section of a fragment map of E. coli strain K12 W3110 strain (red).
Supplemental Data Figure 8. Part of the distance matrix, representing the similarity between
the clinical isolates from MA1124 to MA1142. The differences equal (1 – SSI), where SSI is the
sample similarity index. Smaller values correspond to more similar isolates.
White, E.J., et al. 12
Supplemental Data Tables
Supplemental Data Table S1. Known S. aureus strains used in this study.
Strain name Common name Source1) Strain name Common name Source1)
NRS12) Mu50 NARSA NRS383 USA200 NARSA NRS22) Mu3 NARSA NRS384 USA300-0114 NARSA NRS22 USA600 NARSA NRS385 USA500 NARSA NRS702) N315 NARSA NRS386 USA700 NARSA NRS712) Sanger 252 NARSA NRS387 USA800 NARSA NRS722) Sanger 476 NARSA NRS4822) USA300 NARSA NRS772) NCTC 8325 NARSA NRS483 USA1000 NARSA NRS1002) COL NARSA NRS484 USA1100 NARSA NRS1232) MW2/USA400 NARSA 35556 SA113 ATCC NRS382 USA100 NARSA
1) NARSA, Network on Antimicrobial Resistance in Staphylococcus aureus program (supported
under NIAID, NIH Contract No. HHSN272200700055C); ATCC, American Type Culture
Collection.
2) Strains with known genome sequences.
White, E.J., et al. 13
Supplemental Data Table S2. Isolate source and antimicrobial sensitivity Sa
mpl
e ID
Isolated From Sample Origin
Cef
azol
in
Clin
dam
ycin
Eryt
hrom
ycin
Levo
floxa
cin
Oxa
cilli
n
Rifa
mpi
n
Tetr
acyc
line
Trim
/Sul
fa
Vanc
omyc
in
1168 5) urine outpatient R1) N/A N/A R R R S2) S S 1126 skin, left leg outpatient R R R R R S S S S 1128 sputum inpatient R R R R R S S S S 1138 sputum inpatient R R R R R S S S S 1144 bronchial lingular lavage inpatient R R4) R R R S S S S 1166 right wrist drainage inpatient R R4) R R R S S S S 1167 sputum outpatient R R4) R R R S S S S 1229 sputum inpatient R R R R R S S S S 1156 abdomen inpatient R R R R R S R S S 1133 skin, axilla outpatient R S R R R S S S S 1152 swab #2, drainage outpatient R S R R R S S S S 1151 swab #1, drainage outpatient R S R I3) R S S S S 1153 abdominal abscess drainage outpatient R S R I R S S S S 1142 back outpatient R S R I R S S S S 1170 left leg drainage outpatient R S R R R S S S S 1154 left leg drainage outpatient R S R S R S S S S 1135 axila left drainage outpatient R S R S R S S S S 1230 left axilla drainage outpatient R S R S R S S S S 1139 left buttock drainage outpatient R S R S R S S S S 1143 skin, left leg outpatient S S R S S N/A S S S 1134 bronchial wash inpatient S R4) R R S N/A S R S 1155 toe drainage outpatient S R R S S N/A R S S 1125 left thigh drainage outpatient S S R S S N/A R S S 1124 sinus drainage outpatient S S S S S N/A R S S 1233 skin, deep finger outpatient S S S S S N/A S S S 1157 skin, toe inpatient S R4) R S S N/A S S S 1131 right shoulder drainage outpatient S S S S S N/A S S S 1141 right breast skin outpatient S S S S S N/A S S S 1158 right ear drainage outpatient S R R S S N/A S S S 1137 skin, right index finger outpatient S S S S S N/A S S S 1145 nasal drainage outpatient R S S I R S S S S 1129 blood outpatient S S S S S N/A S S S 1169 blood inpatient S S S S S N/A S S S 1171 finger inpatient S S S S S N/A S S S 1140 left hand drainage outpatient S S S S S N/A S S S 1159 left leg drainage inpatient S S S S S N/A S S S 1160 right leg drainage inpatient S S S S S N/A S S S 1173 skin, axilla outpatient S S S S S N/A S S S 1228 sputum outpatient S S S S S N/A I S S 1127 skin, wound outpatient S S S S S N/A S S S 1130 right thigh drainage outpatient S S S S S N/A S S S 1132 right foot drainage outpatient S S S S S N/A S S S 1136 elbow drainage outpatient S S S S S N/A S S S 1146 right eye drainage inpatient S S S S S N/A S S S 1147 abscess drainage outpatient S S S S S N/A S S S 1148 skin, lip ulcer outpatient S S S S S N/A S S S 1149 skin, toe outpatient S S S S S N/A S S S 1150 skin outpatient S S S S S N/A S S S 1165 nares surveilance inpatient S S S S S N/A S S S 1172 sputum inpatient S S S S S N/A S S S 1174 left fifth finger inpatient S S S S S N/A S S S 1227 skin, left axilla outpatient S S S S S N/A S S S
White, E.J., et al. 14
1) R = Resistant to antimicrobial agent (MIC Interpretive Standard)
2) S = Sensitive to antimicrobial agent (MIC Interpretive Standard)
3) I = Intermediate resistance to antimicrobial agent (MIC Interpretive Standard)
4) Isolate displays inducible clindamycin resistance
5) Sample identification is random
White, E.J., et al. 15
Supplemental Data Table S3. Theoretical (seq.) and DLA-measured (obs.) DNA fragments
generated by restriction enzyme SanDI.
Seq.1) Obs. Seq.1) Obs. Seq.1) Obs. Seq.1) Obs. Seq.1) Obs. Seq.1) Obs. Seq.1) Obs. Seq.1) Obs. Seq.1) Obs.232 231 231 228 231 229 189 189 264 268 242 244 184 183 265 263 205 204201 202 201 198 201 200 155 156 252 253 180 179 180 179 206 203 180 180152 193 152 193 178 178 149 150 206 202 160 161 164 164 191 189 164 179178 178 178 176 159 160 128 128 191 188 150 151 149 150 180 179 148 150159 159 159 159 148 150 123 124 180 177 150 151 134 134 179 178 133 136148 148 148 148 134 134 118 120 177 175 134 135 116 118 166 165 117 118134 134 134 134 131 132 100 101 164 162 116 117 111 111 164 163 109 112132 133 132 132 122 124 94 96 146 143 109 111 90 89 144 144 90 92115 115 115 115 110 111 142 141 108 110 89 89 135 137 88 91110 110 110 111 100 102 133 132 90 91 133 134
133 132 90 91 133 134117 117 89 89 117 116113 113 71 70 113 113101 100 62 64 105 104
91 90 101 101
Total2) 1561 1560 1514 1056 2410 1751 1217 2332 1234Fract3) 0.54 0.54 0.55 0.36 0.86 0.62 0.43 0.83 0.43
Mu50 Mu3 N315 MW2 USA300Sanger 252 Sanger 476 NCTC 8325 COL
1) Sequence can be found at: http://www.ncbi.nlm.nih.gov/genomes/lproks.cgi
2) Total amount of the genome in kilobases measured by DLA
3) Fraction of the genome measured by DLA
White, E.J., et al. 16
Supplemental Data Table S4. Protocol for isolation, purification, and site-specific tagging of
Staphylococcus aureus genomic DNA.
Step Buffer Volume,1) Finj,2) Ftan,2) Temp. Time, mL mL/min mL/min ºC min Prime chamber 0.1×B1,3) 0 0 0 40 0 Inject cells 0.1×B1 0.7 0.1 0 40 7 Inject lytic solution,3) 0.1×B1 0.4 0.1 0 40 4 Incubate 0.1×B1 NA NA NA 40 32 Inject SDS buffer,3) TE + 0.1%SDS 0.2 0.05 0 40 4
Wash with SDS buffer TE + 0.1%SDS 6 (3)4) 0.8 0.75 40 7.5
(3.75)4) Inject UL buffer,3) TE + 0.1%SDS 0.075 0.05 0 40 1.5 Inject PK solution,3) TE 0.4 0.05 0 40 8 Incubate TE NA NA NA 58 18 Cool down TE 1 0.35 0 24 2.85 Inject SDS buffer TE + 0.1%SDS 0.2 0.05 0 40 4
Wash with SDS buffer TE + 0.1%SDS 6 (3)4) 0.8 0.75 40 7.5
(3.75)4)
Wash with TES,3) TE + 200 mM NaCl 10 (5)4) 0.8 0.75 40 12.5
(6.25)4) Incubate with TES TE + 200 mM NaCl NA NA NA 40 21 Inject RE buffer,3) RE Buffer 0.2 0.05 0 40 4 Wash with RE buffer RE Buffer 5 0.8 0.75 40 6.25 Inject RE,3) RE Buffer 0.4 0.05 0 40 8 Incubate with RE RE Buffer NA NA NA 40 29.35 Wash frit TE + EDTA 2 0.35 0 40 5.7 Inject with TE + EDTA TE + EDTA 0.2 0.05 0 40 4 Wash with TE + EDTA TE + EDTA 5 0.8 0.75 40 6.25 Wash with TE buffer TE 5 0.8 0.75 40 6.25 Inject bisPNA,3) TE 0.5 0.05 0 40 10 Incubate with bisPNA TE NA NA NA 68 17.3 Cool down TE 1 0.35 0 24 2.85 Inject TES buffer TE + 200 mM NaCl 0.2 0.05 0 40 4 Wash with TES TE + 200 mM NaCl 13.4 0.53 0.48 40 25.3 Incubate with bisPNA TE + 200 mM NaCl NA NA NA 68 10 Cool down TE 1 0.35 0 24 2.85 Inject TES buffer TE + 200 mM NaCl 0.2 0.05 0 40 4 Wash with TES TE + 200 mM NaCl 2.5 0.53 0.48 40 4.7 Wash with TE TE 9 0.53 0.48 40 17 Wash frit TE 2 0.35 0 40 5.7
Total Time
303.35(289.6)4)
White, E.J., et al. 17
1) Total volume of the injected solution.
2) Finj and Ftan are injection and tangential flow rates, respectively. Normal flow rate is the
difference between the injection and tangential flow rates.
3) B1 buffer, 50 mM Tris pH 8.0, 0.5% Tween 20, 0.5% TX-100; Lytic solution, 150,000 U of
lysozyme, 1,000 U of achromopeptidase, 120 U of lysostaphin, and 6 µg/mL of RNAse A in
1×B1 buffer; SDS buffer, 0.1% SDS in TE buffer; UL buffer, 50mM Tris pH 8, 10mM EDTA,
1% SDS, 2% β-mercaptoethanol; PK solution, 4 µg/mL of proteinase K in UL buffer (universal
lysis buffer); TES buffer, 200 mM NaCl in TE; RE buffer, 200mM potassium acetate, 50mM
Tris pH 7.6, 20mM magnesium acetate; RE, 100 U of SanDI restriction enzyme in RE buffer, 6
µg/mL RNAse A; bisPNA, 2 µM of bisPNA 268 in TE buffer.
4) A variation of the protocol parameters during repeated measurements of Mt. Auburn Hospital
isolates presented in parenthesis.
White, E.J., et al. 18
Supplemental Data Figures
A
C D
250 kb
100 kb
B
SmaI: Set 1
* * * * *Mu5
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200
USA
300-
0114
USA
500
USA
800
USA
1000
USA
1100
250 kb
100 kb
SanDI: Set 2
* * * * *USA
600
USA
100
CO
L
USA
200
USA
300-
0114
USA
500
USA
800
USA
1000
USA
1100
250 kb
100 kb
250 kb
100 kb
SanDI: Set 2
* * * * *USA
600
USA
100
CO
L
USA
200
USA
300-
0114
USA
500
USA
800
USA
1000
USA
1100
SanDI: Set 2
* * * * *USA
600
USA
100
CO
L
USA
200
USA
300-
0114
USA
500
USA
800
USA
1000
USA
1100
250 kb
100 kb
SanDI: Set 1
* * * * *Mu5
0
MW
2/U
SA40
0
USA
700
USA
300
SA11
3
Sang
er 2
52
Sang
er 4
76
Mu3
N31
5
250 kb
100 kb
250 kb
100 kb
SanDI: Set 1
* * * * *Mu5
0
MW
2/U
SA40
0
USA
700
USA
300
SA11
3
Sang
er 2
52
Sang
er 4
76
Mu3
N31
5
SanDI: Set 1
* * * * *Mu5
0
MW
2/U
SA40
0
USA
700
USA
300
SA11
3
Sang
er 2
52
Sang
er 4
76
Mu3
N31
5
Supplemental Data Figure 1.
White, E.J., et al. 19
A
B20
15
10
5
0
Pho
ton
Inte
nsity
(a.u
.)
150100500
Length (kb)
Mu3
Mu50
Pho
ton
Inte
nsity
(a.u
.)
Length (kb)
20
15
10
5
150100500
0
A
B20
15
10
5
0
Pho
ton
Inte
nsity
(a.u
.)
150100500
Length (kb)
20
15
10
5
0
Pho
ton
Inte
nsity
(a.u
.)
150100500
Length (kb)
Mu3
Mu50
Pho
ton
Inte
nsity
(a.u
.)
Length (kb)
20
15
10
5
150100500
0
Pho
ton
Inte
nsity
(a.u
.)
Length (kb)
20
15
10
5
150100500
0
20
15
10
5
150100500
0
Supplemental Data Figure 2.
White, E.J., et al. 20
Supplemental Data Figure 3.
White, E.J., et al. 21
MA
1129
MA
1132
MA
1140
MA
1146
MA
1159
MA
1160
MA
1169
MA
1171
MA
1173
MA
1174
MA
1131
MA
1136
MA
1141
MA
1145
MA
1147
MA
1148
MA
1150
MA
1157
MA
1165
MA
1172
MA
1228
MA
1124
MA
1125
MA
1127
MA
1130
MA
1134
MA
1142
MA
1149
MA
1155
MA
1227
MA
1233
MA
1133
MA
1135
MA
1139
MA
1143
MA
1151
MA
1152
MA
1153
MA
1154
MA
1170
MA
1230
MA
1126
MA
1128
MA
1137
MA
1138
MA
1144
MA
1156
MA
1158
MA
1166
MA
1167
MA
1168
MA
1229
MA
1129
MA
1132
MA
1140
MA
1146
MA
1159
MA
1160
MA
1169
MA
1171
MA
1173
MA
1174
MA
1129
MA
1132
MA
1140
MA
1146
MA
1159
MA
1160
MA
1169
MA
1171
MA
1173
MA
1174
MA
1131
MA
1136
MA
1141
MA
1145
MA
1147
MA
1148
MA
1150
MA
1157
MA
1165
MA
1172
MA
1228
MA
1131
MA
1136
MA
1141
MA
1145
MA
1147
MA
1148
MA
1150
MA
1157
MA
1165
MA
1172
MA
1228
MA
1124
MA
1125
MA
1127
MA
1130
MA
1134
MA
1142
MA
1149
MA
1155
MA
1227
MA
1233
MA
1124
MA
1125
MA
1127
MA
1130
MA
1134
MA
1142
MA
1149
MA
1155
MA
1227
MA
1233
MA
1133
MA
1135
MA
1139
MA
1143
MA
1151
MA
1152
MA
1153
MA
1154
MA
1170
MA
1230
MA
1133
MA
1135
MA
1139
MA
1143
MA
1151
MA
1152
MA
1153
MA
1154
MA
1170
MA
1230
MA
1126
MA
1128
MA
1137
MA
1138
MA
1144
MA
1156
MA
1158
MA
1166
MA
1167
MA
1168
MA
1229
MA
1126
MA
1128
MA
1137
MA
1138
MA
1144
MA
1156
MA
1158
MA
1166
MA
1167
MA
1168
MA
1229
Supplemental Data Figure 4.
White, E.J., et al. 22
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0
False Positive Rate
True
Posi
tiveR
ate
Oxacillin
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0
False Positive Rate
True
Posi
tiveR
ate
Oxacillin
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0
False Positive Rate
True
Posi
tiveR
ate
Oxacillin
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0
False Positive Rate
True
Posi
tiveR
ate
Oxacillin
Supplemental Data Figure 5.
White, E.J., et al. 23
Filter by brightness Filter hairpins
Identify length standardCalibrate length
ReportSearch fragments
Characterize detection parameters, cluster statistics
Filtration and calibration
Read and interpolate traces
Direct Linear Analysis (DLA)
Identification and analysis of DNA fragments
Preliminary clustering
Merge similar clusters
Cluster by correlation coeff.
Cluster by probability distance
Clustering
Filter by brightness Filter hairpins
Identify length standardCalibrate length
ReportSearch fragments
Characterize detection parameters, cluster statistics
Filtration and calibration
Read and interpolate traces
Direct Linear Analysis (DLA)
Identification and analysis of DNA fragments
Preliminary clustering
Merge similar clusters
Cluster by correlation coeff.
Cluster by probability distance
Clustering
Supplemental Data Figure 6.
2.3 kb
White, E.J., et al. 24
Matching algorithm currently covers the following scenarios
A fragment from Sample 1 matching a fragment from Sample 2
150 kb
150 kb
A fragment from Sample 2 matching part of a fragment from Sample 1
50 kb
100 kb
Part of a fragment from Sample 1 matching a fragment from Sample 2
250 kb
220 kb
B
Sample 1 Sample 2A
E. coli K12 MG1655 vs. K12 W3110 example
C
Matching algorithm currently covers the following scenarios
A fragment from Sample 1 matching a fragment from Sample 2
150 kb
150 kb
A fragment from Sample 2 matching part of a fragment from Sample 1
50 kb
100 kb
Part of a fragment from Sample 1 matching a fragment from Sample 2
250 kb
220 kb
B Matching algorithm currently covers the following scenarios
A fragment from Sample 1 matching a fragment from Sample 2
150 kb
150 kb
A fragment from Sample 2 matching part of a fragment from Sample 1
50 kb
100 kb
Part of a fragment from Sample 1 matching a fragment from Sample 2
250 kb
220 kb
Matching algorithm currently covers the following scenarios
A fragment from Sample 1 matching a fragment from Sample 2
150 kb
150 kb
A fragment from Sample 1 matching a fragment from Sample 2
150 kb
150 kb
A fragment from Sample 2 matching part of a fragment from Sample 1
50 kb
100 kb
A fragment from Sample 2 matching part of a fragment from Sample 1
50 kb
100 kb
Part of a fragment from Sample 1 matching a fragment from Sample 2
250 kb
220 kb
Part of a fragment from Sample 1 matching a fragment from Sample 2
250 kb
220 kb
B
Sample 1 Sample 2A Sample 1 Sample 2Sample 1Sample 1 Sample 2Sample 2A
E. coli K12 MG1655 vs. K12 W3110 example
C
E. coli K12 MG1655 vs. K12 W3110 exampleE. coli K12 MG1655 vs. K12 W3110 example
C
Supplemental Data Figure 7.
White, E.J., et al. 25
A1124_0A1125_0A1126_0A1127_0A1128_0A1129_0A1130_0A1131_0A1132_0A1133_0A1134_0A1135_0A1136_0A1137_0A1138_0A1139_0A1140_0A1141_0A1142_01124_ 0.001125_ 0.01 0.001126_ 0.55 0.62 0.001127_ 0.57 0.47 0.71 0.001128_ 0.67 0.68 0.06 0.63 0.001129_ 1.00 1.00 1.00 1.00 1.00 0.001130_ 0.01 0.00 0.48 0.47 0.53 1.00 0.001131_ 0.69 0.53 0.58 0.84 0.55 1.00 0.53 0.001132_ 1.00 1.00 1.00 1.00 1.00 0.52 1.00 1.00 0.001133_ 0.43 0.43 0.55 0.66 0.45 1.00 0.43 0.70 1.00 0.001134_ 0.10 0.01 0.54 0.30 0.59 1.00 0.01 0.66 1.00 0.43 0.001135_ 0.44 0.43 0.55 0.66 0.52 1.00 0.43 0.70 1.00 0.00 0.43 0.001136_ 0.55 0.64 0.59 0.53 0.56 1.00 0.55 0.78 1.00 0.65 0.72 0.66 0.001137_ 0.73 0.52 0.59 0.66 0.56 1.00 0.61 0.87 1.00 0.92 0.60 0.92 0.82 0.001138_ 0.49 0.56 0.00 0.65 0.06 1.00 0.41 0.58 1.00 0.48 0.54 0.48 0.59 0.59 0.001139_ 0.43 0.43 0.55 0.66 0.52 1.00 0.43 0.70 1.00 0.00 0.43 0.00 0.65 0.92 0.48 0.001140_ 1.00 1.00 0.87 1.00 1.00 0.83 1.00 1.00 0.82 1.00 1.00 1.00 0.92 1.00 0.87 1.00 0.001141_ 0.62 0.69 0.76 0.78 0.74 1.00 0.69 0.01 1.00 0.70 0.76 0.76 0.84 0.87 0.76 0.70 1.00 0.001142_ 0.45 0.44 0.55 0.67 0.46 1.00 0.44 0.71 1.00 0.23 0.45 0.24 0.66 0.92 0.49 0.23 1.00 0.71 0.00
Supplemental Data Figure 8.