For optimal performance and accurate validation, all ingredients used in your local validation process must meet specific quality standards. Below are the essential criteria for both raw milk and antibiotics.
Note on Raw Milk Samples
Unpreserved, co-mingled raw milk samples from cows are usually the basis for testing across most dairy analysis laboratories globally. However, a minority of samples submitted for analysis may also come from other species (e.g., most commonly goat and sheep milk🔗), or other dairy matrices🔗. In all cases, it is important to first define the sample scope of your local validation framework. For samples with preservatives, we advise working closely with us to first properly analyse your preservative (e.g., composition, concentration, volumetric conditions, etc.), as a pre-feasibility check before defining the scope of your local validation.
Raw, Co-mingled Cow Milk Samples
For the raw, co-mingled cow milk used in testing, it must be of high quality and adhere to the standards outlined in ISO 23758 Technical Guideline🔗. Therefore, to ensure consistency in test results the following specifications apply.
| Parameter | Raw Co-mingled Cow Milk Specification |
| Sample Source | Raw, commingled milk from a minimum of four untreated animals in mid-lactation (60~200 days after calving), with no antibiotics having been administered (untreated). |
| Fat | 35~45g/L |
| Protein | 30~36g/L |
| SCC* | < 400,000 |
| TBC/BCC** | < 100,000 |
| pH | 6.6~6.9 |
* Somatic Cell Count
** Total Bacterial Count or Bacterial Cell Count
Antibiotics
For reliable testing, use pure antibiotic substances. Below are the specific antibiotics required, along with their respective grades and molecular properties.
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Penicillin G main (potassium salt) 1,600 units/mg 113-98-4
e.g. or equivalent🔗
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Oxytetracycline (dihydrate)
e.g. or equivalent🔗
-
Sulfadiazine 99.0 68-35-9
e.g. or equivalent🔗
⏭️ Next article: Weight and Dilution of Antibiotics🔗
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