which method of urine collection is best for urinalysis?

Urinalysis is used in lab testing to detect disease and manage various health conditions. These include liver disease, kidney disease, diabetes and UTIs (urinary tract infections). Some employers also request their employees and job candidates to undergo urine collection to test for drug use by urinalysis. 

Many addiction treatment and recovery programs require routine urine testing to screen for alcohol and drug use, which can help identify a relapse during recovery. A urine test is also used to detect drug use in professional athletes. This is in fulfillment of the anti-doping restrictions enforced by the WADA (World Anti-Doping Agency), and others.

How Is Liquid Urine Analysis Performed?

Three lab methods are used in analyzing liquid urine. One is a visual exam that checks the urine for color and clarity. The second is a microscopic exam that checks for the presence of blood or tumor cells, parasites, etc. The third is a dipstick test where a thin plastic strip laced with chemicals is dipped into the urine. If anything is abnormal, the chemicals react and change color.

How Is Urine Collected for Analysis?

Traditionally, a research team, clinician or lab will issue a specimen cup that a person uses to self-collect their midstream urine. This involves placing the specimen cup under the stream of urine to catch a sample as instructed.

In addition to being messy, this method of urine collection poses various challenges. The liquid specimen samples are vulnerable to contamination and adulteration that could affect the results by producing false negatives or false positives. Also, liquid urine samples require expensive refrigeration between 2° - 8°C to maintain stability during transportation.

In hospital settings, urine collection methods aim for more sterile samples. Four commonly used hospital methods include:

1. Clean-catch (CC)
2. Sterile urine bag
3. Suprapubic aspiration (SPA)
4. Urethral catheterization (Cath)

Catherization (Cath) and suprapubic aspiration (SPA) are believed to give the most reliable results, as they minimize false positives. However, they are invasive and painful. The urine bag method is an easy alternative, but has a higher rate of producing false positives. The clean-catch (CC) method is a modified approach to the pee-in-a-cup method described above, whereby a patient wipes the area clean before self-collecting a midstream urine sample. Although it is non-invasive, at least one study found that the midstream clean-catch technique may not decrease contamination rates.

Dried Urine Sampling (DUS)

Another method of urine collection for lab analysis is dried urine sampling. It still involves collecting liquid urine into a cup or tube, but an additional step is to place small drops of the collected urine as spots on a special filter paper for dried urine sampling, or DUS. The dried urine spots are intended to dry on the filter paper.

Alternatively, you can collect urine microsamples on the tip of a Mitra^® device. With this method, the liquid urine is collected into a cup or tube, and the absorbent VAMS^® tip of the Mitra device is then dipped onto the surface of the liquid sample until the tip is saturated. The sampled device tips are then allowed to dry. They are then sealed into a pouch that fits inside a mailing envelope, which can be sent to the lab via regular mail. Once in the lab, they will be analyzed as dried urine samples.

Why Choose DUS Over Other Methods?

Dried Urine Sampling presents many advantages compared to liquid urine collection methods, including:

• Sample stability towards enzymatic and bacterial activity
• Easy, inexpensive storage and transportation options
• DUS processing can be automated in the lab
• Minimal training is required for specimen collection
• DUS methods save time and costs
• Dried samples are not easy to dilute or adulterate
• You can collect a fixed volume of urine

Using Dried Urine Sampling With The VAMS Method

Many end-users find that collecting urine on the absorbent VAMS tip of the Mitra device is easier than trying to add a tiny spot to a filter card. Study volunteers can use Mitra devices to easily collect their samples at home and mail them to the designated lab.

This enables research organizations to conduct remote urine microsampling studies. The Mitra devices prevent the deterioration of the samples collected, which leads to higher sample success rates with reliable lab data.

Image credits: Trajan, Neoteryx, Shutterstock