Description
According to the European Commission Directive 2002/86/EC, food ingredients must be declared and in the case of meat products, the specification of the animal species has to be disclosed on the label. Species authenticity can be extremely relevant to consumer for a variety of reasons, including economic, medical and religious reasons. Fraudulent substitution by less expensive meats, inclusion of meat in vegetarian products or the presence of allergens are all issues of major concern.
Several methods for species detection that are available are based on protein identification (by means of electrophoretic and/or immunological methods). However, these methods are not reliable for highly processed and heated products due to protein denaturation and degradation.
As DNA is much more stable, PCR/qPCR amplification of a species-specific target sequence provide a simple, fast and reliable method for the detection of a target species with high sensitivity and specificity, even in the case of highly fragmented DNA.
The Xpert qDetect Sheep Kit is a kit for the detection by qPCR of DNA from Sheep (Ovis aries) present in total DNA previously purified from food samples. This kit is compatible with instruments equipped with FAM and ROX channels. The detection limit is 10-100 pg of Ovine DNA, allowing the detection of as little as 0.1% of target DNA in food samples if 100ng of total DNA (mixed species) is used
FEATURES
Fast, Easy and Reliable
LOD: 10 pg of target DNA
Compatible with instruments equipped with FAM and ROX channels
100% Specificity
A total of 13 non-target species (10 Animal and 3 Plant species), related with the target and/or commonly found in the same food products, were tested in triplicate for exclusivity, using 100ng of purified genomic DNA. None of the testes species showed a positive result.
List of specied used for exclusivity test:
A001 Cow (Bos taurus), A002 Swine (Sus domesticus), A003 Horse (Equus ferus caballus), A004 Duck (Anas platyrhynchos domesticus), A005 Chicken (Gallus gallus domesticus), A006 Turkey (Meleagris gallopavo), A007 Goat (Capra hircus), A009 Ostrich (Struthio camelus), A010 Deer (Cervus elaphus), A011 Quail (Coturnix coturnix), A012 Partridge (Perdix perdix), A013 Pheasant (Phasianus colchicus), A014 Rabbit (Oryctolagus cuniculus), P001 Potato (Solanum tuberosum), P002 Corn (Zea mays), and P003 Soybean (Glycine max).
Suitability of the DNA extracts was confirmed by PCR amplification of the ITS region using universal primers and species identification was confirmed by sequencing of mitochondrial genes.
Trueness
Trueness of the method was evaluated using 10 positive and 8 negative food samples obtained commercially, comprising 11 different matrices:
Sheep meat, Sheep cheese, Meat mix, Pate, Turkey ham, Turkey mortadella, Cooked meal in gallipot, Pastry, Casings cow with chickpea (canned cooked meal), Casings cow with spicy sausage (canned cooked meal), Duck rice (cooked meal).
All samples were tested in triplicate. All samples presented the epected results for all the replicates. Hence a 0% false positive rate and a 0% false negative rate, corresponding to a trueness of 100%
