Laboratory Services 



C. Reference Diagnostic Services 



1. Indirect Immunofluorescence (IF) Test 



As a general rule, only paired (or serial) acute-phase and convalescent-phase sera 

 should be submitted. Ideally, the acute-phase serum should be collected during the first 

 week of illness, and the convalescent-phase serum should be obtained 3 wk after onset 

 of illness. Titers usually peak at approximately 5 wk after onset. 



Place the acute-phase serum in a 1-dram screw-capped glass vial. Seal the vial with 

 waterproof tape, label for proper identification, and store at 4°C. Prepare a second vial 

 for the convalescent-phase senmi. When both sera are ready, tape the two vials together 

 to avoid separation in transit and mail them with CDC Fonn 3.203 to CDC. If you 

 subsequently receive additional convalescent-phase sera from the same patient, please 

 submit them to CDC with appropriate identification, a CDC Form 3.203, and a state- 

 ment that previous sera from this patient were submitted for the indirect IF test. 



If we do not receive an acute-phase senim collected dunng the first week of 

 illness, we will perform the indirect IF test on a single serum collected at least 14 days 

 after onset of illness. However, because a single serum specimen obtained before this 

 time and submitted for indirect IF testing will not be evaluated without justification, 

 we strongly urge that every attempt be made to obtain a second sample. Sera from 

 blood samples obtained just before a patient dies or during autopsy will be tested, with 

 the understanding that we may not find a significant titer. 



Address requests for indirect IF and other serologic tests to: 



Center for Disease Control 

 Attention: Dr. Hazel W. Wilkinson 



Special Immunology Laboratory 



DASH-Unit 10 



Bacterial Immunology Branch 



Bureau of Laboratories 

 Atlanta, Georgia 30333 

 Telephone (404) 329-3929 



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