Fingernail Resources

No. The results of any second collected specimen have absolutely no bearing on the validity of the results of the first collected specimen. Furthermore, each matrix has its own advantages, disadvantages and limits of interpretation.

No, the result of any second collected specimen has absolutely no bearing on the validity of the result of any first collected specimen because you have no idea what the donor did between time A and time B.

Yes, environmental exposure versus ingestion must be resolved when interpreting drug tests using fingernails.

Yes, the results can be different. Each specimen type has its own advantages, disadvantages, threshold to positivity, and detection time window. One test does not refute the other. The test results are cumulative. For instance, if the maternal urine is positive for cocaine and newborn meconium is positive for methamphetamine, the results do not rule each other out. The appropriate interpretation is that the mother consumed both cocaine and methamphetamine.

No, when testing a reservoir specimen type, a specimen type where analytes tend to accumulate, you may not backtrack to determine time, dosage, or frequency. The result is positive or negative for the appropriate detection window associated with the specimen type.

No, the sample may be shipped ambient.

No, the use of any product that contains isopropanol will NOT explain the presence of EtG. Isopropanol forms its own glucuronide, isopropyl glucuronide and does not interfere with the LC-MS/MS detection of ethyl glucuronide (EtG).

No. These specimen types act as a reservoir, where drugs and their metabolites may accumulate and/or degrade over time. When testing any reservoir matrix, it is impractical to back-track to determine time, dosage or frequency. There are too many variables involved. The reported values (the numbers) have no therapeutic or clinical value. You cannot use the number to estimate how much the donor used or to what extent the donor was exposed.

No, Lidocaine will NOT explain a GCMS or LCMSMS confirmed positive cocaine or cocaine metabolite in any specimen type (blood, urine, hair, nails, meconium, umbilical cord segment, etc…). The compounds are very structurally different and breakdown into very different metabolites.

Yes, the results can be different. Each specimen type has its own advantages, disadvantages, threshold to positivity, and detection time window. One test does not refute the other. The test results are cumulative. For instance, if the maternal urine is positive for cocaine and newborn meconium is positive for methamphetamine, the results do not rule each other out. The appropriate interpretation is that the mother consumed both cocaine and methamphetamine.

Yes, the analysis of a number of tissue types for the presence of drugs of abuse has been used in every state for decades. Specifically, our umbilical cord testing has been used to provide evidence of drug use by the mother in numerous states. Additionally, the detection of drug in umbilical cord was used as evidence of maternal drug consumption in a murder case in South Carolina and that interpretation was upheld on appeal to the SC Supreme Court.

Drugs are distributed via the blood supply to the nail cells and the nail bed. Nails grow not only in length but in thickness as well. As the nail grows in thickness, it creates layers of drug history.

The optimum amount of nail clippings needed is 100 milligrams. If trimming all 10 fingernails, each clipping must be at least 2 millimeters to 3 millimeters long.

There are too many variables for anyone to know time of use, dosage, or frequency from the result(s) of a drug test. Reservoir matrices such as hair, fingernail, umbilical cord, and meconium continuously collect drug and alcohol biomarkers. This makes it difficult to determine specific details of use. Because the biomarker is collected over a period of time, the results represent total accumulation that cannot be pin-pointed to specific times/dates/dosages, etc.

No. When testing a reservoir specimen type, a specimen type where analytes tend to accumulate, you may not backtrack to determine time, dosage, or frequency. The result is positive or negative for the appropriate detection window associated with the specimen type.

A: For urine testing, it is standard practice in the field of toxicology to include both EtS and EtG, because EtG is subject to bacterial production and degradation if a urine sample is contaminated (e.g. when the donor has a urinary tract infection). EtS is not subject to bacterial production or degradation, and provides a second, more reliable alcohol biomarker in these urine contamination scenarios. Other specimens types, such as fingernails and hair, do not have this issue, so only EtG is measured in those sample types.

There are several explanations for this.

1. Different sample matrices have different detection time frames. The result of any second collected specimen has no bearing on the validity of a first collected specimen. For example, a hair sample with a 3-month detection window might test positive for a particular substance, while a urine sample from the same donor, with a 2-3 day detection window, might test negative. In this case, the donor has used that substance within the past 3-months, but may not have used it within the most recent 3-days.
2. The result of any second collected specimen has no bearing on the validity of a first collected specimen. Therefore, a negative result observed for the umbilical cord does not refute a positive result observed on the maternal urine specimen and the reverse is true as well. There are many legitimate reasons for discrepant urine and umbilical cord results.
3. The urine specimen was a screen-only result and was not confirmed using an appropriate mass spectrometric method. The screen-only urine result is a clinically valid result, however, without an appropriate mass spectrometric confirmation, the urine result has no value in a forensic proceeding.
4. Lastly, some placentas can prevent some compounds from reaching the fetus. There are documented cases of maternal ingestion without in utero exposure.

Single doses do not guarantee a positive result. The number of doses required to generate a positive result is highly variable between donors.