Please Remove Adblock
Adverts are the main source of Revenue for DoveMed. Please remove adblock to help us create the best medical content found on the Internet.

Wet Prep Test

Last updated March 18, 2018

Approved by: Maulik P. Purohit MD, MPH

The Wet Prep Test, or Wet Mount Test, is the microscopic analysis of a sample that has been placed on a microscope slide, along with a drop of water or other solution.

What are the other Names for this Test? (Equivalent Terms)

  • Wet Mount Test

What is Wet Prep Test? (Background Information)

  • The Wet Prep Test, or Wet Mount Test, is the microscopic analysis of a sample that has been placed on a microscope slide, along with a drop of water or other solution. It is used to observe the microorganisms in a sample, in a watery environment
  • Water is added to fill the space between the microscope slide and the cover slip, adding stability and support. It also provides an environment in which the microbes can move, allowing for an accurate study of their behavior
  • A Wet Prep Test is especially useful when observing the movement of microorganisms. Certain microbes possess tail-like structures, called flagella, which can be seen in action via the wet prep
  • Flagella help propel the organism through its watery environment. They also contribute to an organism’s ability to cause disease. Flagella help the pathogen maneuver through bodily fluids and reach a site of infection
  • The Wet Prep Test is often performed on samples taken from the female genital tract. The vagina normally contains a diverse population of microorganisms, including bacteria and fungi. Generally, these exist with one another in harmony, and are in fact beneficial for maintaining the health of the vaginal tract
  • Certain factors lead to a disruption in the balance of the microorganism population within the vaginal tract. Such factors include antibiotics, immune deficiencies, and sexual activity
  • Disease may occur, if the microorganism populations are unbalanced. This may result from antibiotic use, sexual intercourse, changes in diet, and stress levels, all of which influence the microorganism populations
  • Both aerobic and anaerobic bacteria are found within the female genital tract:
    • Aerobic organisms use oxygen to produce energy. Examples of such organisms include Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis
    • Anaerobic bacteria, which do not use oxygen to produce energy, include Lactobacillus species. They are the most common forms in the genital tract
  • When aerobic bacteria, such as E. coli, outnumber the native anaerobic bacteria, such as Lactobacilli, aerobic vaginitis (AV) may result. This is distinct from bacterial vaginosis (BV), in which anaerobic bacteria are the main causative organisms
  • The Wet Prep Test is used to observe the behavior and movement of microorganisms in a sample. It is also used to identify organisms based on their movement patterns and physical characteristics. It is also used to identify sperm

What are the Clinical Indications for performing the Wet Prep Test?

Following are the clinical indications for performing the Wet Prep Test:

  • Suspected rape
  • Vaginal pain or irritation
  • Foul-smelling vaginal discharge
  • Soreness
  • Rash
  • Itching
  • Trouble urinating
  • Redness or swelling at the site of injury
  • Pus

How is the Specimen Collected for Wet Prep Test?

Following is the specimen collection process for Wet Prep Test:

Sample required: Fluid sample from the site of infection.

Process: Swabbing the infection site with a Q-tip shaped device.

Preparation required: No special preparation is needed prior to the test.

What is the Significance of the Wet Prep Test Result?

The Wet Prep Test may reveal infection, if pathogenic microorganisms are observed. It is most commonly used on samples taken from the vagina. Some common infections of the vagina include:

  • Bacterial vaginosis (BV)
  • Aerobic vaginitis
  • Trichomoniasis
  • Vaginal yeast infection

The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.

Additional and Relevant Useful Information:

  • The Wet Prep Test may also be used to investigate a rape case by examining for the presence of semen
  • Aside from causing discomfort, aerobic vaginitis may also lead to miscarriage and preterm labor and delivery

Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider of the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.

The following DoveMed website links provide more information on various vaginal infections:



Please visit our Laboratory Procedures Center for more physician-approved health information:


References and Information Sources used for the Article:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: Sept. 13, 2015
Last updated: March 18, 2018