Skip Ribbon Commands
Skip to main content
Sign In
Navigate Up

23134 Glucose, Fasting

Glucose, Fasting
Test Code: FBS
Synonyms/Keywords
​​Glucose Fasting Blood Sugar, i-Stat Fasting Blood Sugar​
Useful For
Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders, including diabetes mellitus, neonatal hypoglycemia and idiopathic hypoglycemia, and pancreatic islet cell carcinoma.​
Specimen Requirements
 
 
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume
 Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)

Yes

8 Hours​

​		 Plasma/Serum​Lithium-heparin Plasma Separator (PST)​, Serum Separator Tube (SST)
Lithium or Sodium-heparin Green Top (GTT), Red Top Tube (RTT)
Gray Top (GYTT)​
1 mL​0.3 mL​​
​i-Stat only = Whole Blood​Lithium-heparin Green Top Tube (GTT)​​1 mL​200 uL ​
Collection Processing Instructions
Patient is to be fasting for 8 hours prior to specimen collection. Water is permitted during the fasting period.
Samples collected in tubes without gel barriers must be centrifuged and removed from the cells within one hour for storage or transport.
Samples collected in gel barrier tubes must be centrifuged and removed from the primary tube prior to transporting to Marshfield. Do not send the primary collection tube. Indicate time of collection.
i-Stat:  Sample must be tested within 10 minutes of collection.
Specimen Stability Information
Specimen Type Temperature Time
Plasma/Serum​ ​ ​ Ambient​ 5 days​
Refrigerate​ 7 days​
Frozen​ 1 year
​i-Stat Whole Blood ​Ambient ​10 minutes
Rejection Criteria
Specimens in contact with cells for more than 2 hours without a preservative (fluoride/oxalate)
​i-Stat testing:  clotted samples
​i-Stat testing:  anticoagulants other than lithium heparin
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Bloomer ​​Monday through Friday ​Less than 2 hours​ ​Amperometrical/i-Stat
​Cadott ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Chetek ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Chippewa Falls ​​Monday through Friday ​Less than 2 hours​ ​Modified Hexokinase Method/Siemens Dimension
​Colby/Abbotsford ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Cornell ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Cumberland ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Weston
 ​Monday through Sunday​ ​Less than 2 hours​ ​​Modified Hexokinase Method/Siemens Dimension
​Eagle River ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Eau Claire ​Monday through Sunday​ ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU
Park Falls
 ​Monday through Sunday​ ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU
​Hayward ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Ladysmith Medical Center ​​Monday through Sunday ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU​
​Lakeview Medical Center ​Monday through Sunday​ ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU
Marshfield​ Monday through Sunday​ Less than 2 hours​ Hexokinase-UV/NAD Endpoint Assay/Beckman AU
​Mercer ​​Monday through Friday ​Less than 2 hours​ ​Amperometrical/i-Stat​
​Minocqua ​Monday through Sunday​ ​Less than 2 hours​ Hexokinase-UV/NAD Endpoint Assay/Beckman AU
Mosinee​ ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Neillsville​Monday through Sunday​​​Less than 2 hours​​Modified Hexokinase Method/Siemens Dimension
​Oakwood ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Phillips ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Rhinelander ​Monday through Friday ​Less than 2 hours ​Amperometrical/i-Stat
​Stettin ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Stevens Point ​​Monday through Friday ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU ​
Wisconsin Rapids​ ​​Monday through Friday ​Less than 2 hours​ ​​Modified Hexokinase Method/Siemens Dimension
​Wittenberg ​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
Reference Range Information
Performing Location Reference Range
All Performing Sites 70-99 mg/dL (fasting)​
​See Critical Value List for list of current critical values ​
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
82947   ​ ​ ​ ​ ​
Synonyms/Keywords
​​Glucose Fasting Blood Sugar, i-Stat Fasting Blood Sugar​
Ordering Applications
Ordering Application Description
​Centricity ​Glucose, Fasting
​Cerner ​Glucose Fasting
​COM ​Glucose, Fasting -Blood
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
 
 
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume
 Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)

Yes

8 Hours​

​		 Plasma/Serum​Lithium-heparin Plasma Separator (PST)​, Serum Separator Tube (SST)
Lithium or Sodium-heparin Green Top (GTT), Red Top Tube (RTT)
Gray Top (GYTT)​
1 mL​0.3 mL​​
​i-Stat only = Whole Blood​Lithium-heparin Green Top Tube (GTT)​​1 mL​200 uL ​
Collection Processing
Patient is to be fasting for 8 hours prior to specimen collection. Water is permitted during the fasting period.
Samples collected in tubes without gel barriers must be centrifuged and removed from the cells within one hour for storage or transport.
Samples collected in gel barrier tubes must be centrifuged and removed from the primary tube prior to transporting to Marshfield. Do not send the primary collection tube. Indicate time of collection.
i-Stat:  Sample must be tested within 10 minutes of collection.
Specimen Stability Information
Specimen Type Temperature Time
Plasma/Serum​ ​ ​ Ambient​ 5 days​
Refrigerate​ 7 days​
Frozen​ 1 year
​i-Stat Whole Blood ​Ambient ​10 minutes
Rejection Criteria
Specimens in contact with cells for more than 2 hours without a preservative (fluoride/oxalate)
​i-Stat testing:  clotted samples
​i-Stat testing:  anticoagulants other than lithium heparin
Useful For
Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders, including diabetes mellitus, neonatal hypoglycemia and idiopathic hypoglycemia, and pancreatic islet cell carcinoma.​
Reference Range Information
Performing Location Reference Range
All Performing Sites 70-99 mg/dL (fasting)​
​See Critical Value List for list of current critical values ​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Bloomer ​​Monday through Friday ​Less than 2 hours​ ​Amperometrical/i-Stat
​Cadott ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Chetek ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Chippewa Falls ​​Monday through Friday ​Less than 2 hours​ ​Modified Hexokinase Method/Siemens Dimension
​Colby/Abbotsford ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Cornell ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Cumberland ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Weston
 ​Monday through Sunday​ ​Less than 2 hours​ ​​Modified Hexokinase Method/Siemens Dimension
​Eagle River ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Eau Claire ​Monday through Sunday​ ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU
Park Falls
 ​Monday through Sunday​ ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU
​Hayward ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Ladysmith Medical Center ​​Monday through Sunday ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU​
​Lakeview Medical Center ​Monday through Sunday​ ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU
Marshfield​ Monday through Sunday​ Less than 2 hours​ Hexokinase-UV/NAD Endpoint Assay/Beckman AU
​Mercer ​​Monday through Friday ​Less than 2 hours​ ​Amperometrical/i-Stat​
​Minocqua ​Monday through Sunday​ ​Less than 2 hours​ Hexokinase-UV/NAD Endpoint Assay/Beckman AU
Mosinee​ ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Neillsville​Monday through Sunday​​​Less than 2 hours​​Modified Hexokinase Method/Siemens Dimension
​Oakwood ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Phillips ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Rhinelander ​Monday through Friday ​Less than 2 hours ​Amperometrical/i-Stat
​Stettin ​​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
​Stevens Point ​​Monday through Friday ​Less than 2 hours​ ​​Hexokinase-UV/NAD Endpoint Assay/Beckman AU ​
Wisconsin Rapids​ ​​Monday through Friday ​Less than 2 hours​ ​​Modified Hexokinase Method/Siemens Dimension
​Wittenberg ​Monday through Friday ​Less than 2 hours​ ​​Amperometrical/i-Stat
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
82947   ​ ​ ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.