BS ISO 18074:2015 pdf download

BS ISO 18074:2015 pdf download.Textiles — Identification of some animal fibres by DNA analysis method — Cashmere, wool, yak and their blends
1 Scope
This International Standard specifies a testing method for DNA analysis of some animal fibres to identify cashmere, wool, yak, and their blends by using extraction, amplification by the polymerase chain reaction (PCR) method and DNA detection processes.
This International Standard is applicable to cashmere, yak, and wool and their blends as a qualitative method.
2 Caution
Test results for fibre identification by the DNA analysis method can be obtained with a high accuracy for the above-mentioned textile products which were processed at lower dye concentration levels or dyed in light colours.
However, when such textile products were processed under severe conditions or high temperatures,the mitochondrial DNA could have been damaged. In such cases, identification can be difficult because amplification of DNA by PCR cannot take place. If textile products were contaminated by using products from another species, such as cashmere grease on wool fibres, this situation may be solved by checking using microscopy techniques.
3 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 8655-2, Piston-operated volumetric apparatus — Part 2: Piston pipettes
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1 DNA
deoxyribonucleic acid, that exists in nuclei and in mitochondria of animal fibre cells and is composed of a linear array of 4 bases (Adenine: A, Thymine: T, Guanine: G and Cytosine: C)
Note 1 to entry: The DNA sequence is identical and intrinsic for each animal fibre.
4.2 animal fibres
cashmere, wool, or yak fibres
9.4 DNA purification
Follow the procedure described in 9.4.1 to 9.4.13.
9.4.1 Add 300 μl of sodium perchlorate solution (7.3) to the micro tube of 9.3.6. Then, shake it for 10 min at a condition of 500 r/min using the shaking machine (6.6).
9.4.2 Add 300 μl of chloroform/isoamyl alcohol (7.2) to the micro tube of 9.4.1. Tumble it about for 10 s by hand. Then, shake it for 10 min using the shaking machine (6.6) (e.g. at 500 r/min for rotating shaker, 100 r/min for reciprocal shaker) or equivalent instrument (e.g. 30 r/min for vertical rotator) to mix well. The solution will become clear.
9.4.3 Centrifuge the micro tube of 9.4.2 at 3 300g for 1 min at room temperature. Then, take 500 μl of supernatant solution using a pipette (6.1) and put it in a new micro tube.
9.4.4 Add 500 μl of chloroform/isoamyl alcohol (7.2) to the micro tube of 9.4.3. Tumble it about for 10 s by hand. Then, shake it for 10 min using the shaking machine (6.6) or equivalent instrument to mix well. The solution will become clear.