2. BARCODEBARCODE: A barcode is an optical machine-readable representation
of data, which shows data about the object to which it attaches.
Originally, barcodes represented data by varying the widths and spacings
of parallel lines, and may be referred to as linear or 1 dimensional (1D),
rectangular or geomatrical shapes (2D). 3D barcode uses the height of the
line to represent a product.
1D 2D 3D
3. DNA barcode
• DNA barcoding is a taxonomic method that
uses a short genetic marker in an organism's
DNA to identify it as belonging to a
particular species.
4. The basic concept of bar-code DNA. It carries
with it a large number of oligonucleotides per
protein binding event, there is substantial
amplification and one can detect PSA at 30
attomolar concentration.
Alternatively, one can do polymerase chain
reaction on the oligonucleotide barcodes and
boost the sensitivity to 3 attomolar.
11. Ho et al., 2005. Multiplexed Hybridization Detection with Multi color
Colocalization of Quantum Dot Nanoprobes. Nano Lett., Vol. 5, No. 9, 2005
12. Sequences of the Three Anthrax-Related Targets (rpoB, capC,
and pagA) and Their Associated Oligonucleotide Probes.
13. Simulated multiplexed analysis of anthrax-related genetic targets for pathogenicity: (a) color pallet for the three
pairs of targetspecific QD nanoprobes and their resulting colocalized fluorescent images upon sandwich
hybridization;
(b) four samples containing different combinations of the three targets, rpoB, capC, and pagA. Checks represent
the existence of certain target sequences. Sample IV does not
contain any target and is used as a negative control.
(c) Fluorescent images I, II, III, and IV correlate with samples I, II, III, and IV, respectively.
17. Magnetic Particle
Probe
Target Protein
Nanoparticle Probe
with Barcode DNA
Separation using
magnetic field &
Bardcode DNA
dehybridization
Barcode DNA
Signal Amplification
by PCR
Chip based detection of Barcode DNA
a : complementary capture DNA
b : non complementary capture DNA
atto molar detection!!atto molar detection!!
Nanoparticle-Base Bio-BarcodesNanoparticle-Base Bio-Barcodes
Ultrasensitive Protein Detection
18. The system is based on magnetic microparticle probes with antibodies that
specifically bind a target of interest [prostate specific antigen (PSA), amyloid
beta oligomer] and nanoparticle probes that are encoded with DNA that is
unique to the protein target of interest and antibodies that can sandwich the
target captured by the microparticle probes .
Magnetic separation of the complexed probes and target followed by
dehybridization of the oligonucleotides on the nanoparticle probe surface
allows one to determine the presence of the target protein by identifying the
oligonucleotide sequence released from the nanoparticle probe
Nanoparticle-Based Bio-Bar Codes for the Ultrasensitive
Detection of Proteins
