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Test Code PHBF pH, Body Fluid

Reporting Name

pH, BF

Useful For

Indicating the presence of infections or fistulas


Verifying the effectiveness of treatment to reduce stomach pH


Diagnosing disease states characterized by abnormal stomach acidity


This test is not appropriate for measurement of pleural fluid pH as that measurement should be made using a blood gas analyzer locally due to sample stability and transport requirements.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Body Fluid

Necessary Information

1. Date and time of collection.

2. Specimen source

-Preferred: Identify source name from the following list with location (if appropriate):

 -Peritoneal fluid (peritoneal, abdominal, ascites, paracentesis)

 -Drain fluid (drainage, JP drain)

 -Synovial fluid

-Write in source name with source location (if appropriate)

-Unacceptable: Spinal fluid (CSF), chest (thoracic) fluid, thoracentesis, pleural fluid, and urine

Specimen Required

Supplies: Metal Free Specimen Vial (T173)

Container/Tube: Metal-free container

Specimen Volume: 5 mL

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Body Fluid Refrigerated (preferred) 7 days
  Frozen  7 days
  Ambient  24 hours

Reference Values

An interpretive report will be provided.

Day(s) Performed

Monday through Sunday

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
UPHB pH, BF 2748-2


Result ID Test Result Name Result LOINC Value
U_PHB pH, BF 2748-2
SRC18 Source 14725-6

Method Description

The pH meter is composed of a glass electrode, calomel electrode and voltmeter. The glass electrode has a fixed acid concentration, yielding a corresponding voltage. The calomel electrode is the reference electrode. Its voltage is independent of the H+ ion concentration. The two electrodes constitute a galvanic cell whose electromotive force is measured by the voltmeter. The meter is calibrated to read in pH units, reflecting the H+ ion concentration. The meter is used to determine pH in 0 to 14 range.(Instruction manual: Fisher Scientific accumet Basic (AB) Benchtop Meters. Fisher Scientific; 07/2018)

Report Available

Same day/1 day

Reject Due To

Spinal, chest (thoracic) fluid, thoracentesis, or pleural fluid

Method Name

pH Meter

Secondary ID