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Test Code BTK Prot Exp BTK Protein Expression

Important Note

Due to staffing changes, the IDL is not currently accepting samples. For more information contact the Immunology Diagnostics Laboratory (IDL) at

Clinical System Name

BTK Protein Expression


BTK Flow Cytometry

Agammaglobulinemia, X-Linked



The protein encoded by this gene plays a crucial role in B-cell development.  Mutations in this gene cause X-linked agammaglobulinemia type 1, which is an immunodeficiency characterized by the failure to produce mature B lymphocytes, and associated with the failure of Ig heavy chain rearrangement.

Sample Requirements

Specimen:  Whole Blood

Container(s):  Dark Green/Sodium Heparin (no serum separator)

Preferred Vol:  10-20 mL

Minimum Vol:  5-7 mL (for young children only)


Note: Specimens stable for only 24 hours at room temperature.



  Collected in-house at Seattle Children's Collected off-site (including SCH Bellevue)
M-Th collect any time collect any time
Friday must be received by main lab before 9 AM to ensure noon delivery to IDL must be received at IDL before 12 noon Friday
Saturday do not collect do not collect
day before a holiday ok if collected before 9 AM must be received at IDL before 12 noon day before holiday
Sunday ok if collected after 12 noon (to be tested next morning)

ok if collected after 12 noon- must be received at IDL before 12 noon next day

Sunday before a holiday Monday do not collect do not collect
Holiday ok if collected after 12 noon (to be tested next morning)

ok if collected after 12 noon -must be received at IDL before 12 noon next day




Specimen Type Temperature Time
Whole Blood Room temp 24 h
  Refrigerated N
  Frozen N



STAT Performed TAT
N Monday - Thursday; must be in lab before noon 4-6 weeks


Processing Instructions

Reject due to: Clotted specimens, microtainers, refrigerated, samples received > 24 hours post-collection

Spin: N

Aliquot: N

Temp: Room Temperature

Storage location: Notify Sendouts Lab immediately.  Place whole blood in CPA room temp send-outs rack. Store extra labels in the clear plastic box attached to CPA refrigerator.


Off-site collection: It is critical that the samples be kept at room temperature; use extra packing to maintain temperature.  If specimen will not arrive at Immunology Diagnostic Laboratory before noon for same day testing, blood should be drawn as late in the day as possible, maintained at room temperature and sent overnight to allow test set-up the following morning.  Testing must be set up within 24 hours of collection.  The lab accepts samples Monday through Friday but samples should be shipped only Monday through Thursday so they do not sit over the weekend. 


Transport sample at room temperature via overnight shipping to:


 Seattle Children's Research Institute

Immunology Diagnostic Laboratory

1900 9th Avenue JMB-7

Seattle, WA 98101-1304 

Performing Laboratory

Seattle Children's Laboratory


Department:  Immunology Diagnostic Laboratory

Address:  1900 9th Avenue JMB-7, Seattle, WA 98101-1304

Phone: 206-987-7435



Lab Client Services: 206-987-2617,

CPT Codes

88184, 88185, 88187




Method: Flow Cytometry

Analytical Volume: 5mL

Reference Range

Reference values accompany patient report.


IDL Requisition

Special Instructions

Links to:  Immunology Diagnostic Laboratory