Ultrasensitive flow-based immunoassays using single-molecule counting.
BACKGROUND
Immunoassay (IA) technology has expanded the clinical utility of protein biomarkers, but demands for increased sensitivity, dynamic reporting ranges, and small sample volumes have limited the potential clinical usefulness of many biomarkers. We assessed the performance, including limits of detection (LODs) and the dynamic reporting range, of an IA-based technology, Erenna Immunoassay System, for a series of biomarkers, including cardiac troponin I (cTnI).


METHODS
Erenna IAs were used with 10 different and clinically important biomarkers to ascertain the LOD with various sample sizes (10 microL to 200 microL).


RESULTS
The Erenna Immunoassay System generated LODs of 10-100 pg/L using 100 microL of sample. For cTnI, the LOD was 0.2 ng/L and a 10% CV was seen between 0.78 and 1.6 ng/L.


CONCLUSIONS
The Erenna IA-based technology reproducibly measures protein biomarkers with detection limits of 10-100 pg/L, with a dynamic range of >4.5 logs in sample volumes of 50-150 microL.
Todd
John
J
Singulex, Inc., Hayward, CA 94545, USA. j.todd@singulex.com
Freese
Bob
B
Lu
Ann
A
Held
Douglas
D
Morey
Jennifer
J
Livingston
Richard
R
Goix
Philippe
P
D000818:Animals; D015415:Biomarkers / Q000097:blood; D004285:Dogs; D000882:Haplorhini; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood
D015415:Biomarkers; D019210:Troponin I