Evaluating mixtures of 14 hygroscopic additives to improve antibody microarray performance.
Microarrays allow the miniaturization and multiplexing of biological assays while only requiring minute amounts of samples. As a consequence of the small volumes used for spotting and the assays, evaporation often deteriorates the quality, reproducibility of spots, and the overall assay performance. Glycerol is commonly added to antibody microarray printing buffers to decrease evaporation; however, it often decreases the binding of antibodies to the surface, thereby negatively affecting assay sensitivity. Here, combinations of 14 hygroscopic chemicals were used as additives to printing buffers for contact-printed antibody microarrays on four different surface chemistries. The ability of the additives to suppress evaporation was quantified by measuring the residual buffer volume in open quill pins over time. The seven best additives were then printed either individually or as a 1:1 mixture of two additives, and the homogeneity, intensity, and reproducibility of both the spotted protein and of a fluorescently labeled analyte in an assay were quantified. Among the 28 combinations on the four slides, many were found to outperform glycerol, and the best additive mixtures were further evaluated by changing the ratio of the two additives. We observed that the optimal additive mixture was dependent on the slide chemistry, and that it was possible to increase the binding of antibodies to the surface threefold compared to 50 % glycerol, while decreasing whole-slide coefficient of variation to 5.9 %. For the two best slides, improvements were made for both the limit of detection (1.6× and 5.9×, respectively) and the quantification range (1.2× and 2.1×, respectively). The additive mixtures identified here thus help improve assay reproducibility and performance, and might be beneficial to all types of microarrays that suffer from evaporation of the printing buffers.
McGill University & Genome Quebec Innovation Centre, McGill University, 740 Dr. Penfield Avenue, Montreal, Quebec, Canada, H3A 0G1.|Biomedical Engineering Department, McGill University, 3775 University Street, Montreal, Quebec, Canada, H3A 2B4.
Sébastien
S
Bergeron
McGill University & Genome Quebec Innovation Centre, McGill University, 740 Dr. Penfield Avenue, Montreal, Quebec, Canada, H3A 0G1.|Biomedical Engineering Department, McGill University, 3775 University Street, Montreal, Quebec, Canada, H3A 2B4.|Neurology and Neurosurgery Department, McGill University, 3801 University Street, Montreal, Quebec, Canada, H3A 2B4.
Veronique
V
Laforte
McGill University & Genome Quebec Innovation Centre, McGill University, 740 Dr. Penfield Avenue, Montreal, Quebec, Canada, H3A 0G1.|Biomedical Engineering Department, McGill University, 3775 University Street, Montreal, Quebec, Canada, H3A 2B4.
Pik-Shan
PS
Lo
McGill University & Genome Quebec Innovation Centre, McGill University, 740 Dr. Penfield Avenue, Montreal, Quebec, Canada, H3A 0G1.|Biomedical Engineering Department, McGill University, 3775 University Street, Montreal, Quebec, Canada, H3A 2B4.
Huiyan
H
Li
McGill University & Genome Quebec Innovation Centre, McGill University, 740 Dr. Penfield Avenue, Montreal, Quebec, Canada, H3A 0G1. david.juncker@mcgill.ca.|Biomedical Engineering Department, McGill University, 3775 University Street, Montreal, Quebec, Canada, H3A 2B4. david.juncker@mcgill.ca.|Neurology and Neurosurgery Department, McGill University, 3801 University Street, Montreal, Quebec, Canada, H3A 2B4. david.juncker@mcgill.ca.
David
D
Juncker
D000906:Antibodies / Q000737:chemistry; D001622:Betaine / Q000737:chemistry; D002021:Buffers; D002072:Butylene Glycols / Q000737:chemistry; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D019855:Ethylene Glycol / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D005990:Glycerol / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D053583:Interleukin-1beta / Q000032:analysis; D057230:Limit of Detection; D011327:Printing; D040081:Protein Array Analysis / Q000295:instrumentation* / Q000379:methods*; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000032:analysis; D015203:Reproducibility of Results; D012996:Solutions; D014835:Volatilization; D017155:Wettability; D019014:fas Receptor / Q000032:analysis
D000906:Antibodies; D002021:Buffers; D002072:Butylene Glycols; C491901:FAS protein, human; D005456:Fluorescent Dyes; D053583:Interleukin-1beta; D047889:Receptors, Tumor Necrosis Factor, Type II; D012996:Solutions; D019014:fas Receptor; D001622:Betaine; C026978:2,3-butylene glycol; D019855:Ethylene Glycol; D005990:Glycerol; D004121:Dimethyl Sulfoxide
Antibody; Contact printing; Hygroscopic; Low evaporation; Microarray; Protein; Reproducibility