Which of the following are important aspects to consider in conducting accurate drug testing?

A. the length of time since the person last took the drug
B. the type of drug test being conducted (e.g., urine, saliva, hair)
C. having a qualified person directly observe the collection of the sample (e.g., urine, saliva, hair)
D. following an established rigid chain of custody to ensure that the sample collected is accurately labeled, secured, stored, and tested

Typical biological samples taken for estimation of the drug concentration are blood, urine, saliva and hair. The wide acceptance for test is the blood. For accurate testing the chain of custody of the samples should be maintained since the time the samples are collected to the laboratory analysis and finally to the presentation of the samples in the court of law.

The samples should be collected in appropriate containers and contamination should be prevented as this can lead to errors in the result. These samples should be stored in the containers where they remain prevented from the degradation. Testing using latest technology or improvisation of the old technology.