|
| |
Stringent Quality
Control Measures for Microarray Printing are Followed for every "print run":
-
Visual Inspection-
We validate every production lot of arrays using a visual-light scan of
representative slides, allowing the identification of missed or inadequately
deposited samples.
-
Internal
Control-
We use a proprietary labeling methodology to attach a fluorescent tag to
substrate-bound nucleic acids. This assay is quantitative and provides an
accurate measure of determining the relative levels of bound probe. For each
printing lot, several (“QC sacrifice”) slides from the beginning, middle and the
end of the run are examined using this assay. An image of the reaction,
intensity data, and an overall intensity histogram from each representative
slide is provided in the QC report.
-
Batch
Quality Control-
Every array in a batch and every package of printed arrays are closely
scrutinized before shipping to detect adequate sample deposition, oligo
coupling, surface chemistry anomalies and oligo concentration variations outside
of normal limits. This is accomplished through a variety of imaging modalities
and assays using randomly harvested slides from each print run. The data is
compiled and included into the QC report.
-
Deposition Accuracy-
Our robotic workstations maintain high levels of spatial precision throughout
the printing of every lot. Specifications with regard to absolute array and spot
placement are tightly monitored. The
absolute placement of the first deposition will be limited by the variability of
the slide blank edges, normally ± 100um. After placement of the first
deposition, tolerances will be as specified below. Row and column spacing will
be set per customer specifications.
|
Item |
Specification |
|
Absolute
coordinates of first spot on slide |
X= ± 0.1 mm, Y= ±
0.1 mm |
|
Space between
subarrays |
Per request, ± 50
um |
|
Subarray rotation |
0 ± 0.2 degrees |
|
Row spacing within
a subarray |
Per request, ± 20
um |
|
Column spacing
within a subarray |
Per request ± 20 um |
|
Spots coordinates
within a subarray |
± 20 um shift from
a perfect grid with (to be specified) pitch in X and Y directions |
|
Space between array
copies |
Per request ± 50 um |
|
