Download What Microarrays

Robots for Printing
Microarrays
Jianping Zhou
91.548 Robot 2003 Spring
What Microarrays
 Microarray are high density arrays of biological molecule
elements printed (attached) on a solid microscope slide
using x-y-z stage robotic systems.
 The media carry information through fluorescent intensity,
or ratio of intensities, at a particular location on the array.
 Originally developed by U. Maskos of E.M. Southern in
1992
 Improved in January 1999 by M. Eisen and P. Brown of
Departments of Genetics and Biochemistry and the Howard
Hughes Medical Institute, Stanford University School of
Medicine
 More than 200 companies worldwide engaged in the
Development and application of this technology.
®
GeneChip Probe Array
Why Microarrays
Investigate the patterns and differences of
biologic molecular structure in a single
experiment
Microarray analysis techniques make possible
simultaneously analyze the expression levels
of large numbers of genes and study the
activity of whole genomes, rather than the
activities of single, or a few, genes.
Microarray Feature
Content
Nucleic acid, Protein, Organic, Cell, Tissue
Elements
Rows denote genes, column denote experiment
condition / profiles, Oligonucletide
Microarray Feature
High-density
1.28cm
50 ~ 130 um
>25um
< 200 um
~107 oligonucleotides / cm2
Microarray Feature
substrates
Glass, Nylon, other polymers
poly-L-lysine or aminosilane coated glass
dimethyl-sulfoxide
How Microarrays
cDNA-Microarray Process
Signal Intensity Measure
•Average Difference
–Throw out high and low probes
–Exclude any PM-MM more than 3 SDs from
mean
–Average the differences of PM-MM
Robot for Microarrays
Printing Pin
GeneMachine Omni Grid Arrayer (Stanford University)
Robot for Microarrays
(cont.)
Robot System Providers
•Beecher Instruments
<http://www.beecherinstruments.com>
•BioRobotics
<http://www.BioRobotics.com/>
•Cartesian Technologies
<http://www.cartesiantech.com/>
•Engineering Services
<http://www.ESIT.com/>
•Genetic Microsystems
<http://www.geneticmicro.com>
•Genetix
<http://www.genetix.co.uk/>
•Gene Machines
<http://www.genemachines.com>
•Genomic Solutions
<http://www.genomicsolutions.com/>
•Intelligent Automation Systems <http://www.ias.com>
•Packard
<http://www.packardinst.
Microarrayer from IAG
(Brook Automation)
Microarrayer
Microarrayer HT
Four-axis Seiko robotic arm
Reconfigurable head for grid
patterns
12-tip print head
96- or 384-well microtiter plates
onto as many as 100 silanized
glass microscope slides.
Average spot size of 130 µm
Capability to adjust the spot-tospot spacing
Spot 19,200 elements (the
contents of 200 microtiter plates)
or more onto a single slide.
Capable of over 20,000
spots/slide
Speed:
32 features/sec with 32 pin
printhead
48 features/sec with 48 pin
printhead
Large feature tips: 100-150
micron feature size
Small feature tips: 75-100 micron
feature size
BioGrid from BioRobotics
•Density: print up to 83,000
samples per membrane.
•Print heads available for
PCR product and bacterial
clones.
•Compatible with 96 and 384
well microplates
•Friendly software - just fill in
the boxes.
Macroarraying onto nylon membrane
•Track your samples with
automatic bar code reading.
•Speed: array 36,000 clones onto each of
four 22cm membranes in just 1 hour.
•Requires only 60cm x 60cm
of precious bench space.
BioChip Arrayer from
PerkinElmer
High precision plus accurate
delivery - 180 µm spots at 250
µm spacing
A precision X-Y-Z stage
4-PiezoTip transfer head
10 µm resolution in XY
coordinates
50 µm resolution in Z coordinate
Six predefined labware positions
for microplates (96/384/1536)
and glass slides
Microarrays Future
Microarrays contain live cells that express a
cDNA of interest
Fluidic microarrays, a system for massively
parallel signature sequencing (MPSS). 107
randomly ordered microbeads can be analyzed
simultaneously.
A new ‘scanometric’ detection system based on
gold-nanoparticle-promoted silver reduction has
been reported to be 100 times more sensitive than
fluorescence system
Reference
Eisen MB, Brown PO. DNA arrays for analysis of gene
expression. Methods Enzymol. 1999;303:179-205
Dietmar H Blohm* and Anthony Guiseppi-Elie, New
developments in microarray technology. Current Opinion
in Biotechnology 2001, 12:41-47
Priti Hegde, Rong Qi, Kristie Abernathy, Cheryl Gay,
Sonia Dharap, Renee Gaspard, Julie Earle- Hughes,
Erik Snesrud, Norman Lee, and John Quackenbush,A
Concise Guide to cDNA Microarray Analysis,
Biotechniques, 29(3), Sept 2000,548-562