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Red Blood Cell Lower Respiratory Tract Infection Screen (Manual Electrophoresis)

Published: August 9, 2026Updated: August 17, 2026

This test checks for potential red blood cell changes that may indicate an infection in your lower respiratory tract, such as pneumonia or bronchitis. It uses manual electrophoresis to analyze blood components.

Quick summary

["This screening helps identify possible infections in your lungs or airways."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
96727-3
Short code
RBC # Lower resp Manual
Synonyms
RBC # Lower resp Manual
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
4.2
Ref high
5.9
Critical range
2 N/A – 7 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
CPT
85041
SNOMED
900000000000003001
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

The test looks at red blood cells (RBCs) for signs of abnormal patterns that could suggest inflammation or infection in your lungs. Electrophoresis separates blood proteins, including RBCs, to detect any unusual distribution or presence of specific proteins linked to respiratory infections.

How the Test Works

Blood is drawn and processed through manual electrophoresis, a method that separates blood components by size and charge. This helps identify any changes in RBCs that may correlate with lower respiratory infections.

Why It Might Be Ordered

Your healthcare provider may order this test if you have symptoms like persistent cough, fever, shortness of breath, or if you’ve been exposed to respiratory illnesses. It’s also used in certain diagnostic workflows to screen for conditions affecting lung function.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood. If you’re nervous, let your provider know—they can help make it more comfortable.

Reference range

Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A

Specimen: serum

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

RBC Lower Resp Infection Screen

Frequently asked questions

Why did my doctor order this test?
Your doctor may have suspected a lower respiratory infection based on your symptoms or medical history. This test helps assess whether RBC patterns suggest inflammation or infection in your lungs.
What does a positive result mean?
A positive result may indicate abnormal RBC patterns that could signal an infection or inflammation. However, this test is a screening tool—results alone won’t diagnose the condition. Follow-up testing may be needed.
Can I eat or drink before this test?
You can eat and drink normally before this test, as no special preparation is required.
  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 17, 2026. · Read our editorial policy