A robotic system for performing enzyme immunoassays was developed and
evaluated. A Tecan RSP Model 5051 liquid handling system was equipped
to refrigerate samples and their corresponding immunochemical reagents
and to heat four microwell plates during the enzyme immunoassay. A pr
ogram was developed using RSP Integrator AMI software (version 7.30) t
o control robotic arm position, liquid handling, valve control, and ti
ming. Using this automated system, a two-site enzyme immunoassay for 3
6 air samples and 4 controls was performed for four enzymes simultaneo
usly in 5.5 h with an average throughput time of approximately 2 min p
er sample. These assays achieved a detection limit of 0.2 ng/ml and re
sponse ranges of 0.2-20 ng/ml. The intra- and inter-assay reproducibil
ity were <6% CV and the accuracy was generally +/- 2%. Assay character
istics for the automated system were comparable to a manual method. Th
e robotic enzyme immunoassay provides several advantages over the enzy
me activity assays regarding ability to distinguish two or more enzyme
s in a single air sample and one assay format for several enzymes. Thi
s automated system was demonstrated to be highly reliable and reproduc
ible with a significant reduction in the number of steps and attended
time for a technician.