Learning Center

Retest after STD treatment: when to test again for chlamydia, gonorrhea and trichomoniasis, what a test of cure is, and why testing too soon misleads.

Home STD test privacy goes beyond a plain box. See who can see your order, results and billing, and how to protect each step before you buy.

Saliva test cutoff levels explained: the federal ng/mL limits for each drug, how initial and confirmatory cutoffs differ, and how private employers set their own.

12 panel vs 14 panel drug tests compared: what each screens for, where they differ, and how employers and individuals can pick the right urine test.

How accurate is an HPV self-collected sample? See the sensitivity data, which assays qualify, who should not self-collect, and what a positive result means.

Learn how to ship a urine sample to a lab: triple packaging, UN3373 labeling, temperature, chain of custody and common mistakes that get packages rejected.

How accurate is a hair alcohol test? See what EtG cutoffs, sensitivity, cosmetic treatments and lab methods mean for your result, and when to confirm it.

What a GC/MS confirmation costs per specimen, what drives the price up, and how bundled and screen-only pricing compare for employers and individuals.

Compare random selection methods, from simple random to stratified and cluster sampling, and see which ones hold up for workplace drug testing pools.

CLIA is the federal legal floor; CAP is a voluntary, CMS-deemed accreditation. Learn the differences, how each works, and what drug testing buyers should check.

Learn how hair drug test accuracy varies by substance, how bleaching can affect results, and what to ask labs before trusting a positive finding.

Urine sample stability varies by analyte: see when room temperature, refrigeration, or freezing may work, and why the receiving lab's instructions come first.