Reference sera for antinuclear antibodies. II. Further definition of antibody specificities in international antinuclear antibody reference sera by immunofluorescence and western blotting.
OBJECTIVE
To define the fine specificity of the 10 reference sera used for determination of antinuclear antibodies (ANA) and ANA subsets which are available from the Arthritis Foundation (AF) and from the Centers for Disease Control and Prevention (CDC).


METHODS
AF/CDC sera were assessed by experienced laboratory staff, using indirect immunofluorescence and Western blotting.


RESULTS
The original assignment of fluorescence patterns to 4 reference sera was confirmed, and the fluorescence intensities were determined using reference fluorescent beads. On Western blots, sera AF/CDC2 (anti-SS-B/La) and AF/CDC7 (anti-SS-A/Ro) did not detect Ro antigens, sera AF/CDC9 and AF/CDC10 appeared to be monospecific anti-Scl-70 and anti-Jo-1 sera, respectively, serum AF/CDC4 (anti-U1 small nuclear RNP) recognized the 70-kd band, and serum AF/CDC5 recognized the Sm antigen with its multiple bands. Semiquantitative analyses revealed that AF/CDC5, AF/CDC2, and AF/CDC10 were strongly reactive sera, whereas AF/CDC4 and AF/CDC9 were much weaker and should be used at lower dilutions on Western blots.


CONCLUSIONS
The AF/CDC ANA reference sera, originally described as reference reagents for indirect immunofluorescence and double immunodiffusion techniques, are also useful for Western blotting. The data presented herein further support the use of these sera for reference purposes.
Smolen
J S
JS
University of Vienna, Ludwig Boltzmann Institute for Rheumatology, Austria.
Butcher
B
B
Fritzler
M J
MJ
Gordon
T
T
Hardin
J
J
Kalden
J R
JR
Lahita
R
R
Maini
R N
RN
Reeves
W
W
Reichlin
M
M
Rothfield
N
N
Takasaki
Y
Y
van Venrooij
W J
WJ
Tan
E M
EM
D000974:Antibodies, Antinuclear / Q000097:blood* / Q000276:immunology; D000918:Antibody Specificity; D001324:Autoantigens / Q000276:immunology; D015153:Blotting, Western; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D015337:Multicenter Studies as Topic; D012015:Reference Standards; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000276:immunology; D017411:Ribonucleoproteins, Small Nuclear / Q000276:immunology; D055517:snRNP Core Proteins
D000974:Antibodies, Antinuclear; D001324:Autoantigens; D017412:Ribonucleoprotein, U1 Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins