Test Catalog

Test Id : GLBF

Glucose, Body Fluid

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of infection using body fluid specimens

Method Name
A short description of the method used to perform the test

Enzymatic, Hexokinase

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Glucose, BF

Specimen Type
Describes the specimen type validated for testing

Body Fluid

Ordering Guidance

For spinal fluid specimens, order GLSF / Glucose, Spinal Fluid. Testing will be changed to GLSF if this test is ordered on that specimen type.

Necessary Information

1. Date and time of collection are required.

2. Specimen source is required.


Question ID Description Answers
FLD12 Fluid Type, Glucose

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Specimen Type: Body fluid

Preferred Source:

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

-Pleural fluid (pleural, chest, thoracentesis)

-Drain fluid (drainage, JP drain)

-Peritoneal dialysate (dialysis fluid)


-Amniotic Fluid

-Synovial Fluid

Acceptable Source: Write in source name with source location (if appropriate)

Collection Container/Tube: Sterile container

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge to remove any cellular material and transfer into a plastic vial.

2. Indicate the specimen source and source location on label.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross Lipemia Reject
Gross Icterus Reject
Anticoagulant or additive Breast milk Nasal secretions Gastric secretions Bronchoalveolar lavage (BAL) or bronchial washings Colostomy/ostomy Feces Saliva Sputum Cerebrospinal fluid Urine Vitreous fluid Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Body Fluid Refrigerated (preferred) 7 days
Frozen 30 days
Ambient 24 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of infection using body fluid specimens

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Blood glucose is measured to assess the glycemic state of a patient. Body fluid glucose concentrations that are lower than expected indicate increased cellularity and, therefore, glycolysis within the body fluid space. This serves as an indicator of infection or possibly malignancy. Body fluid glucose concentrations are expected to be lower than that found in serum or plasma. Ideally, they are measured in the fasting state, whereby glucose is able to equilibrate into the space the body fluid is contained within.


Pleural fluid:

Low pleural fluid glucose concentrations (<40-60 mg/dL) indicate a complicated parapneumonic or malignant effusion.(1) However, low glucose is not specific for infection or malignancy and may be attributed to hemothorax, tuberculosis, or rheumatoid or lupus pleuritis, among other diseases. pH is the preferred test for making this determination when available.


Pericardial fluid:

Pericardial fluid glucose levels have been investigated on a limited basis. In presumed normal specimens collected during surgery, pericardial fluid-to-serum ratio for glucose was 1.0 (95% CI, 0.8-1.2).(2)


Peritoneal fluid:

Ascitic fluid glucose should be interpreted in conjunction with serum glucose measurement. In a cohort of noninfected patients with alcohol-related cirrhosis, the mean (SD) ascitic fluid-to-serum glucose ratio was 1.04 (0.25).(3) Ascitic fluid glucose may be helpful in differentiating spontaneous bacterial peritonitis from secondary peritonitis caused by bowel perforation.(4) Secondary peritonitis is likely if 2 of the 3 following criteria are met:

1. Total protein is greater than 1 g/dL

2. Lactate dehydrogenase is greater than 225 IU/L (or greater than the upper limit of normal for serum)

3. Glucose is less than 50 mg/dL(4)


Amniotic fluid:

Amniotic fluid is produced by the amnion and placenta, representing a plasma ultrafiltrate. Amniocentesis may be performed to assess fetal distress. Intraamniotic infection or chorioamnionitis is an acute inflammation of the fetal membranes commonly caused by bacterial infection prompting an inflammatory response leading to labor and term or preterm birth.(5) Chorioamnionitis may be symptomatic (clinical) or asymptomatic (histological), occurring most often during prolonged labor or as a consequence of membrane rupture as bacteria have greater opportunity to ascend the lower genital tract to colonize the uterus. Prompt diagnosis and treatment for clinical chorioamnionitis is critical to avoid maternal and fetal morbidity and mortality. Culture and gram stain are often used in the assessment of infection, however, gram stain lacks sensitivity and culture results are not returned in a timely enough manner to make clinical decisions. Low glucose concentrations have been associated with positive culture results and consequently poor outcomes.(6)


Synovial fluid:

Synovial fluid is present in joint cavities and serves a number of important roles in maintaining joint health and mobility. Symptoms of joint problems include pain, swelling, stiffness, or decreased range of motion.


Routine analysis of synovial fluid includes Gram stain, culture, crystal analysis, and cell count with WBC differential. In normal synovial fluid, glucose concentrations are similar to those observed in fasting serum. Low synovial fluid glucose has been associated with septic arthritis or inflammation.(7)

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Provides information to assist in interpretation of the test results

Body fluid glucose concentrations may be decreased due to increased cellular metabolism and should be interpreted in the context of blood glucose concentrations and in conjunction with other laboratory and clinical findings.(8, 9)


Pleural, peritoneal, and pericardial fluid and serum glucose concentrations are similar in the absence of infection.(3)


Transudative pleural fluid glucose concentrations are similar to serum glucose concentrations, while exudates have glucose concentrations less than serum glucose. Glucose levels below 60 mg/dL are typically associated with low fluid pH.(1,10)


Amniotic fluid glucose levels below 16 mg/dL is suggestive of infection.(6)


Synovial fluid glucose concentrations are similar to fasting blood glucose concentrations or approximately 50% of the nonfasting serum glucose concentration under normal conditions. Values below this can be seen with infection.(7)

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Body fluid glucose results are not diagnostic and should be interpreted in conjunction with other laboratory and clinical findings.


Specimens that have cells present, either due to trauma during collection (ie, blood present) or due to infection (ie, bacteria), that are not centrifuged and separated from cells as soon after collection as possible, may have falsely decreased glucose concentrations owing to the continued metabolic action of cells in vitro.


In very rare cases of gammopathy, in particular type IgM (Waldenstrom macroglobulinemia),  may cause unreliable results.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Light RW: Clinical practice. Pleural effusion. N Engl J Med. 2002 Jun 20;346(25):1971-1977

2. Ben-Horin S, Shinfeld A, Kachel E, Chetrit A, Livneh A: The composition of normal pericardial fluid and its implications for diagnosing pericardial effusions. Am J Med. 2005 Jun;118(6):636-640

3. Wilson JA, Suguitan EA, Cassidy WA, Parker RH, Chan CH: Characteristics of ascitic fluid in the alcoholic cirrhotic. Dig Dis Sci. 1979 Aug;24(8):645-648

4. Runyon BA, Hoefs JC: Ascitic fluid analysis in the differentiation of spontaneous bacterial peritonitis from gastrointestinal tract perforation into ascitic fluid. Hepatology. 1984 May-Jun;4(3):447-450

5. Tita AT, Andrews WW: Diagnosis and management of clinical chorioamnionitis. Clin Perinatol. 2010;37:339-354

6. Gonzalez-Bosquet E, Cerqueira MJ, Dominguez C, Gasser I, Bermejo B, Cabero Ll: Amniotic fluid glucose and cytokines values in the early diagnosis of amniotic infection in patients with preterm labor and intact membranes. J Matern Fetal Med. 1999 Jul-Aug;8(4):155-158

7. Margaretten ME, Kohlwes J, Moore D: Does this adult patient have septic arthritis? JAMA. 2007;297:1478-1488

8. Knight JA, Kjeldsberg CR: Cerebrospinal, synovial, and serous body fluids. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. Elsevier, 2007;448

9. Brunzel NA: Pleural, pericardial, and peritoneal fluid analysis. In: Fundamentals of Urine and Body Fluid Analysis. WB Saunders Company. 1994;406

10. Sahn SA: Getting the most from pleural fluid analysis. Respirology. 2012 Feb;17(2):270-277

11. Meyers DG, Meyers RE, Prendergast TW: The usefulness of diagnostic tests on pericardial fluid. Chest. 1997 May;111(5):1213-1221

Method Description
Describes how the test is performed and provides a method-specific reference

Glucose, in the presence of hexokinase, is converted to glucose-6-phosphate (G-6-P). Glucose-6-phosphate dehydrogenase (G-6-PDH) oxidizes G-6-P in the presence of nicotinamide adenine dinucleotide phosphate (NADP) to gluconate-6-phosphate and NADPH. The rate of NADPH formation is directly proportional to glucose concentration and is measured photometrically.(Package insert: Roche glucose reagent. Roche Diagnostics; v15.0, 06/2019)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 3 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 week

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

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  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
GLBF Glucose, BF 2344-0
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
GL_BF Glucose, BF 2344-0
FLD12 Fluid Type, Glucose 14725-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports