Report on the DNA Analysis of Samples Submitted by
CBC Marketplace
Information
The items (listed in Items Receipt 1 section) submitted to the NRDPFC by CBC Marketplace, in July 2016,
consisted of menu items, containing cooked chicken meat, from local fast-food chain restaurants.
Additional a second set of samples was collected in December of 2016 (listed in Items Receipt 2). The second set
of samples was collected from various Subway shops and processed.
Purpose
At the request of CBC Marketplace, the items (listed in the Items Receipt sections) were analyzed to measure the
quantities of chicken ​ (​Gallus gallus) and non-chicken DNA, and to estimate the quantities of meat-derived protein
and non-meat-derived protein.
Items Receipt 1
The following items were received July 2016:

Ite
m
1
2
3
4
5
6
7
8
9
10
11

Restaurant

Description Of Item

Description of Meat

Laboratory ID

A&W
A&W
McDonald’s
McDonald’s
Subway
Subway
Subway
Tim Horton’s
Tim Horton’s
Wendy’s
Wendys

Grilled Chicken Sandwich
Grilled Chicken Sandwich
Grilled Chicken Sandwich
Grilled Chicken Sandwich
Submarine Sandwich
Submarine Sandwich
Submarine Sandwich
Pita Wrap
Pita Wrap
Grilled Chicken Sandwich
Grilled Chicken Sandwich

Individual Patty
Individual Patty
Individual Patty
Individual Patty
Formed Patty
Formed Patty
Cut/diced Pieces
Cut/diced Pieces
Cut/diced Pieces
Individual Patty
Individual Patty

MPAW01
MPAW02
MPMC01
MPMC02
MPSW01
MPSW02
MPSW03
MPTH01
MPTH02
MPWD01
MPWD02

Items Receipt 2
The following were received December 2016:
Ite
m
1
2
3
4
5
6
7
8
9

Restaurant

Description of Item

Description Of Meat

Laboratory ID

Subway
Subway
Subway
Subway
Subway
Subway
Subway
Subway
Subway

Submarine Sandwich
Submarine Sandwich
Submarine Sandwich
Submarine Sandwich
Submarine Sandwich
Submarine Sandwich
Submarine Sandwich
Submarine Sandwich
Submarine Sandwich

Formed Patty
Strip
Formed Patty
Strip
Formed Patty
Strip
Formed Patty
Strip
Formed Patty

191B1
191B2
200F1
200F2
287K1
287K2
1535W1
1535W2
1620B1

 10

Subway

Submarine Sandwich

Strip

1620B2

Upon receipt, all items were stored in Freezer #12 in the Tissue Storage Room and Freezer #9 in the NRDPFC
automation laboratory.
Examination
Test #1
Chicken samples were collected from A&W, McDonalds, Subway, Tim Horton’s, Subway and Wendy’s.
Each sample was sub-sampled 3 times and tested separately for chicken DNA and plant DNA. We were able to
quantify the relative amounts of chicken vs. plant filler in these samples through PCR amplification. All of the
samples had significant amounts of chicken DNA amplification, which was confirmed by DNA sequencing. Only
the subway samples had significant plant DNA amplification, and the DNA sequencing results for these were a
match to soy. The non-subway samples do not appear to have a significant quantity of plant DNA. Based on the
low quantity of plant DNA of the non-Subway samples, we could not continue the analysis on these samples.
Test #2
A second batch of Subway samples were collected and tested for bird and plant DNA. We were able to determine
the relative amounts of bird vs plant DNA within each sample. The original set of subway samples were also
re-run to be sure that we were consistent across both tests. The bird DNA was determined to be chicken and the
plant DNA was determined to be soy product.
Notes
-

-

-

The second test of the non-subway samples yielded basically the same results and we were unable to
determine if a specific plant filler was present, as the amounts of plant DNA were very low in them.
The second batch of subway samples were sampled only 1 time each instead of 3 due to time constraints.
The samples may have more variation in them, as each portion of a sample may contain a different ratio
of chicken/plant filler.
Each quantification of plant and chicken DNA was repeated in both tests were performed at 5 different
DNA dilutions and the results averaged to determine a final percentage. This helps control against
technical errors and increases the accuracy of the test
We are unable to determine the exact soy product that is contained within the chicken.

Summary of Results
The following tables show the final results of the products in question. Table 1 contains the initial samples from
July 2016. Table 2 contains the samples collected in December 2016. Each table compares the relative amount of
chicken DNA vs the amount of plant DNA. A biopsy punch was used to take an approximately 30mg portion
from the interior of each sample​. ​The first set of samples were sub-sampled three times to control for ​potential
uneven distributions of plant filler and chicken within each sample.
Most of these samples contained a percentage of chicken DNA that was in the mid 80’s to low 90’s. We ran the
samples on the ABI3730 sequencer to try and determine the origin of the plant DNA but were unable to determine
any signficant potential filler for these samples. This can be caused by there not being enough of a single plant
species’ DNA; a mixture of different plants present in low quantities will not provide a clean sequence without
additional testing for individual species separately.

 The samples that we received from Subway had a much higher plant DNA percentage than the other samples.
There was enough DNA for us to sequence the product and determine that these samples contained a substantial
amount of soy DNA. The subway samples originally provided we tested a second time along with the second set of
subway samples to confirm the results.

Table 1
Item ID
MPAW01

MPAW02

MPMC01

MPMC02

MPSW01

MPSW02

MPSW03

MPTH01

MPTH02

MPWD01

Subsample
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A

Chicken (​Gallus gallus) Plant DNA Proportion
DNA Proportion (%)
(%)
88.1
11.9
90.2
9.8
91.4
8.6
88.9
11.1
89.5
10.5
88.4
11.6
83.1
16.9
79.9
20.1
88.6
11.4
84.4
15.6
85.6
14.4
88.2
11.8
62.2
37.8
61.6
38.4
68.7
31.3
61.8
38.2
61.9
38.1
58.0
42.0
58.1
41.9
89.2
10.8
45.6
54.4
84.7
15.3
86.2
13.8
88.6
11.4
87.3
12.7
84.9
15.1
87.4
12.6
88.5
11.5

Standard
Deviation
2.7
1.7
1.8
0.4
1.1
1.7
6.5
8.2
2.8
5.9
6.0
3.5
11.8
13.5
11.9
14.8
14.2
12.6
12.1
1.0
7.4
2.9
3.2
1.2
1.0
1.6
4.6
4.5

 MP WD 02

 

Table 2
Item ID
191B
200F
287K
1535W
1620B

Sub-sa
mple
1
2
1
2
1
2
1
2
1
2

Chicken (Gallus gallus)
DNA proportion ( %)
47.6
36.6
48.3
34.7
38.7
38.5
70.3
27.6
44.7
44.6

Plant DNA Proportion
(%)
52.4
63.7
51.7
65.3
61.3
61.5
29.7
72.4
55.3
55.4

Standard
Deviation
17.5
13.0
12.5
7.7
5.1
8.2
17.3
17.8
7.9
29.3

 Appendix: Technical Section
DNA (deoxyribonucleic acid):
Living organisms are made of cells and within most of their cells are chromosomes made up of deoxyribonucleic
acid (DNA). DNA is the blueprint that encodes all the materials needed for the development and function of each
unique organism.
Strands of DNA are made up of four different building blocks known as nucleotides. A DNA sequence can be
determined by knowing the order in which these nucleotides are arranged. While the majority of the nucleotide
sequence does not vary between organisms, small portions vary significantly enough that identification of species
and individuals within a species can be carried out.
DNA Extraction and Quantification:
DNA was extracted from the samples using a MagneSil Max-Yield (Promega) extraction protocol. Extracted DNA
from the case items was quantified using a fluorometer-based PicoGreen (Invitrogen) assay on the BMG FluoStar
Galaxy 96-well plate system. The DNA quantification test is sensitive to 1ng of DNA. Relative plant and chicken
DNA were quantified by separate PCR amplification of a universal plant chloroplast primer and a universal
vertebrate mitochondrial DNA primer. PCR amplifications where performed at 5 different input DNA quantities
and the resulting amplicons DNA quantities were measured by agarose gel electrophoresis stained with Ethidium
Bromide and a PicoGreen assay.
Species Identification:
For species identification a region of the cytochrome oxidase I (COI) gene within the mitochondrial DNA was
amplified using primers designed to amplify most bird species.. Another primer set for a region of the trnL intron
within plant chloroplast DNA designed to amplify most plant species These amplifications are sensitive to 10pg
of DNA. The amplification products were separated on an agarose gel to visualize results. If amplified DNA was
produced, it was then sequenced on an ABI 3730 DNA Analysis System.
These sequences were then compared to several cytochrome oxidase I or trnL sequences respectively, originating
from control sequences of closely related species. Phylogenetic analysis was subsequently carried out to show
which of the sequences within the database was most closely related to those from the samples, thus indicating the
species of origin. Sequences were analysed using the software programs Sequence Analysis 5.4 and the
phylogenetic software package MEGA 6 and the NCBI BLAST database (https://www.ncbi.nlm.nih.gov/).
Standard Deviation:
Samples were quantified at multiple dilutions of input DNA quantities to improve the accuracy of the testing
results. Because the PCR amplifications are sensitive to very low quantities of DNA, multiple tests with decreasing
DNA quantities ensuring the measurements are within the detection limits of the assays used. This also provides a
measure of variation between multiple tests that may result from technical issues.