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The Science Behind the First Check Drug Test

First Check Tests use advanced and proven technology to ensure the most accurate results possible. First Check’s patented home drug test kits use Thin Layer Chromatography (TLC) technology to produce visible, accurate results within minutes.

Here you will find all the information you need about how to take a First Check® Home Drug Test and how the test works. First Check is dedicated to providing you with detailed answers to your questions, offering tips on taking a test, explaining the technology behind the tests, and sharing the ways people have evaded detection of drug use in the past.

What Happens at the Laboratory

When you send your First Check® Home Drug Test sample to us for further analysis, it comes to Keystone Laboratory, a state-of-the-art test laboratory. The lab is dedicated to accurately and confidentially analyzing the results of the urine drug test samples it receives from consumers and institutions across the United States. Using the most sophisticated equipment and technology available and staffed by toxicology professionals, the lab provides the most accurate possible drug test results and delivers answers with absolute discretion.

How the Lab Analyzes Drug Test Urine Samples :

  • Every day, the laboratory processes over 70,000 urine specimens.
  • Each First Check® Home Drug Test sample the lab receives is sorted by test type and its nine digit confidential confirmation number is recorded in the lab’s Automated Results Program. Once tests have been processed, results are made confidentially available 24 hours a day, seven days a week by phone or online through this Automated Results Program.
  • Once First Check samples are organized and documented, lab technicians use a sophisticated instrument such as Gas Chromatography/Mass Spectrometry or GC/MS for short to test the samples. This technology employs two different methods of chemical analysis to identify and measure drug substances present in the urine sample. GC/MS is considered to be the gold standard in laboratory testing for most drugs.
  • The Gas Chromatography (GC) portion of the instrument separates the complicated chemical mixture found in the urine sample into pure chemicals based on the speed at which the chemicals turn into a gas. Some drug chemicals (usually smaller molecules) turn into gas more quickly than other chemicals (those made of larger molecules).
  • Next, the Mass Spectrometer (MS) portion of the instrument identifies specific drug chemicals based on their structure, determining the molecular weight of the chemicals identified during the Gas Chromatography process. An ion source bombards the urine sample’s molecules with electrons, breaking them apart and turning them into positively charged ions. These ions are passed through an electromagnetic filter which sorts the particles based on their molecular weight. A detector counts the number of ions with each specific mass and feeds this data into a computer.
  • The result of the GC/MS process is a detailed report of the chemicals found in the urine sample, even listing the number of nanograms of each compound present in the sample.
  • All negative test showing no drugs present are entered into the Automated
    Results Program.
  • All positive test results showing the presence of drugs are sent to the lab’s Chief Toxicologist for review, after which they are also entered into the Automated Results Program.
  • Positive samples are reported with a nanogram per milliliter (ng/ml) level. This level is not available through the Automated Results Program, but First Check customers may call 1-888-788-5716 speak with a First Check Customer Service Representative, who will disclose these levels.
  • The nanogram level can not tell you how much of a drug was used nor will it indicate a time frame as to when a drug was used. The only time a nanogram level may be helpful is to monitor a chronic or everyday user of marijuana as a way to tell when the drug is leaving the system.