UriSub® – Liquid, Protein-Free Serum Substitute For use in Manufacturing Clinical Chemistry and Immunological Standards and Controls. This product has been proven effective for use with drugs of abuse and pregnancy (HCG), eliminating the need for lyophilization while stabilizing the product at room temperature. Analyte Recovery is close to 100%. Other uses include: Testing materials for urine contamination; Used for diaper and incontinence product development; and, car seat protection.


Urine is a liquid waste product of the body. A healthy person’s urine is amber colored and slightly acid. Normal urine has a specific gravity of 1.022. The major components of the urine are water, urea, creatinine, uric acid, and inorganic salts. The inorganic salts include, sodium, potassium, ammonia, calcium and magnesium.

The condition of urine is often an indication of a person’s health. In addition to normal contents described above, urine carries drug metabolities, certain hormones, reproductive hormones and steroids.

Urine analysis is very popular in determining the concentration of drugs of abuse, therapeutic drugs and plegnancy.

Urinalysis is preferred by doctors in lieu of blood samples. This created a problem for the manufacturer when he had to obtain large quantities of urine to make controls, standards and calibrants to assure the accuracy of the results.

Most manufacturers of urine assay kits depend on their employees to donate urine samples. These urine samples are then combined to make a large pool, which then has to be treated before controls can be manufactured.

Obtaining a large pool of consistent quality is difficult primarily because the majority of donors are either coffee drinkers, on medication, or take vitamins, and/or other commonly used drugs such as aspirin.

Urine also has a bad connotation and the odor makes it a component that most chemists do not like to work with.

To solve the problem of obtaining a consistent quality of urine and also odorless, CST has developed a patented product, UriSub®

UriSub®, a newly developed synthetic urine, has all the characteristics of urine, such as osmolality, specific gravity and pH. In addition, it is stable at room temperature for at least three years. This offers the manufacturer of urine assay kits the optimal alternative solution to the problems of matrix compatibility.

UriSub®, Liquid, Protein-Free Serum Substitute For use in Manufacturing Clinical Chemistry and Immunological Standards and Controls.


UriSub® is a synthetic buffered solution which is physically equivalent to normal urine with respect to:

  • Specific Gravity
  • Viscosity
  • Osmolality

It has no odor, unlike normal urine.

UriSub® contains a preservative which is both bacteriostatic and bactericidal. UriSub® contains no azide or thimerosal.


UriSub® has been used to demonstrate its equivalency in several commercial products. Among these are:

  • Drugs of Abuse
  • Therapeutic Drugs
  • Reproductive Hormones
  • Some Steroids


UriSub® is a synthetic urine for use as a component in preparing standards and controls for in-vitro diagnostic tests. UriSub® should be treated as any other component or ingredient that has to be qualified prior to use. UriSub®, when used in this manner, does not require FDA approval for its use. A Device Master File for UriSub® is pending. UriSub®) is manufactured under the strictest quality control guidelines to ensure quality and lot to lot uniformity.


Among the currently demonstrated applications for UriSub® are:

  • Urine positive and negative controls
  • Calibrators
  • Urine substitute for making controls and standards


How to prepare positive control or reference standards.

Prepare a concentrated solution of the analyte to be spiked in an aqueous or organic solvent. If an organic solvent is used, use the least possible amount of solvent for solution and spiking purposes. This will assure that UriSub® will remain effective.



Human Urine



Lot to lot variability



Unpleasant odor



Costly processing, column purification prior to use



Unpredictable availability