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Test Code Swt Cl Sweat Chloride Collection and Analysis

Important Note

This test requires an appointment with Processing at UH. 

Phone number: Please call 573-771-9357 or 573-771-9300 

Not taking mineralocorticoids. 

The patient should be feeling well on the day of testing.  

The patient must be hydrated. 

Patient should not use any lotions on their arms or legs within 24 hours of testing 

Testing takes 90 minutes, but it might take up to three hours.

Patient Preparation

Asymptomatic patient weight and age requirements:

> 2 kg; > 2 weeks, > 39 weeks of corrected age. 

Symptomatic Patient with meconium ileus:

> 48 hours of age 

Special Collection Instructions

Sweat Collection is only performed by trained personnel during scheduled appointments. 

Minimum Volume

Minimum Volume 

15 uL to be collected, each within 30 min., 2 collections required.

Maximum Volume 

75 uL can be collected, minimum cut off time for collection is 20 min. 

Preferred Specimen

Sweat

Reference Ranges

0 -≤ 29 mmol/L: CF Unlikely 

30 – 59 mmol/L a. Intermediate 

≥60 mmol/L a. Indicative of CF 

Significant Value

>60 mmol/L 

Reportable Units

mmol/L

Reasons for Rejection

Volume less than 15 uL 

Specimen Stability

Capped in Wescor sealable tubes 

3 days at 2-8 degree Celsius 

2 hours at RT 

Performance Information

Days and Time Performed 

Collection Tuesday-Thursday 0900, 100 by appointment only 

Expected Turn Around Time 

Routine: 4 hours 

Stat Availability 

No 

Performing Bench 

UH Chemistry 

Methodology/Method Description 

Coulometry

CPT Codes

89230, 82438