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BILLING
832-770-4686
1400 N Sam Houston Pkwy E, Ste 158 Houston TX 77032
Frequently asked questions
Toxicology
Billing
- 01In our laboratory, we employ immunoassay, LC-MS, and ICP-MS testing methods to attain exceptional sensitivity and specificity. This approach minimizes the likelihood of errors such as false positives and false negatives.
- 02The period during which drug usage can be identified is contingent upon the nature of the drug in question and a range of influencing factors. It is feasible to detect the presence of numerous substances solely in cases of recent consumption or prolonged use, influenced by several parameters including: - The pharmacokinetics of the drug, specifically its half-life or the rate at which it is metabolized and eliminated by the individual’s body, - The individual's state of hydration, - The frequency with which the drug is consumed, - The mode of administration of the drug, - The established cut-off concentration for the detection test. In general, the presence of drugs in an individual's system can range from hours to weeks contingent upon the specific substance involved.
- 03Our confirmatory toxicology and CCM testing is based on the UHPLC-MS/MS, which stands for Ultrahigh Pressure Liquid Chromatography-Tandem Mass Spectrometry and yields the least false positive results in toxicology testing due to its high specificity and sensitivity. This method separates compounds using liquid chromatography and then identifies and quantifies them with high precision through mass spectrometry, not once but twice (tandem). The double mass spectrometry process allows for a detailed analysis of the molecular structure of the compounds, making it extremely effective at distinguishing between substances that are structurally similar. This capability significantly reduces the chance of cross-reactivity and, thus, false positives, making LC-MS/MS one of the most reliable and accurate tools in toxicological analysis.
- 04The cut-off concentration level in quantitative analytical methods refers to the predefined threshold that determines whether a test result is considered positive or negative for a specific substance. It is the minimum amount of the substance that must be present in the sample for it to be detected by the test. This threshold is crucial for ensuring the reliability and accuracy of the test by reducing the chances of false positives or false negatives. In the context of drug testing, for example, the cut-off concentration is the smallest concentration of the drug or its metabolites that must be present in the sample for the result to be reported as positive, helping to distinguish between incidental exposure and actual use.
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