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Genetic testing for *Pneumocystis jirovecii* (formerly *Pneumocystis carinii*) 141-bp DNA sequence (qualitative)

Published: August 9, 2026Updated: August 16, 2026

This test detects the presence of *Pneumocystis jirovecii* DNA in your blood, a fungus that can cause a serious lung infection called Pneumocystis pneumonia (PCP). It’s often used to diagnose or monitor PCP in people with weakened immune systems, such as those with HIV/AIDS or undergoing certain cancer treatments.

Quick summary

["This test helps confirm if you have PCP, a lung infection that can be life-threatening if untreated."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
76412-6
Short code
Sheep PrP codon 141 Bld Genotyp
Synonyms
Sheep PrP codon 141 Bld Genotyp
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
genotyping
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your healthcare provider may recommend this test if you have symptoms like coughing, shortness of breath, or fever, especially if you have a weakened immune system. It’s also used to check if PCP is present before starting treatment or to monitor your response to therapy.

How the Test Works

A small amount of blood is drawn, and the DNA from *Pneumocystis jirovecii* is identified using a polymerase chain reaction (PCR) technique. This method is highly sensitive and can detect even small amounts of the fungus’s genetic material.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have some mild discomfort from the needle, but it usually goes away quickly. If you’re on blood-thinning medication, let your provider know before the test.

What to Expect During the Test

The test involves a simple blood draw, typically taken from a vein in your arm. The sample is then sent to a lab for analysis. Results are usually available within a few days.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Pneumocystis jirovecii PCR (blood)

Frequently asked questions

What does a positive result mean?
A positive result means your blood contains genetic material from *Pneumocystis jirovecii*, which may indicate an active infection called Pneumocystis pneumonia (PCP). Your healthcare provider will work with you to determine the next steps, which may include starting treatment or further testing.
What does a negative result mean?
A negative result means the test did not detect *Pneumocystis jirovecii* DNA in your blood at the time of testing. However, PCP can still be present if the infection is very early or if the sample was not collected at the right time. Follow-up testing or other diagnostic methods may be needed if you have symptoms.
Can this test be used to monitor treatment?
Yes, this test can sometimes be used to monitor treatment for PCP. If you’re receiving antifungal medications, your provider may order follow-up tests to check if the infection is improving or if the treatment needs adjustment.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy