Gordon Robb Operations Director

Gordon RobbOperations Director

Aim of presentationAim of presentation

• Overview of Alba Bioscience Microarray developments

• Highlight manufacturing implications

• Review development and regulatory issues and strategy

• Presentation of some preliminary data

• Focus on microarray technology as the next generation test platform for blood donation screening

• Protein/carbohydrate/cell based arrays (not genetic testing)

• A single platform to combine blood typing, microbiology and virology testing

MicroarrayMicroarray Project AimProject Aim

Current blood testing Current blood testing proceduresprocedures

Y

Based on the principle of antibody:antigen interactions to determine presence or absence

of a target e.g. blood group

Usually performed in liquid phase

Current Testing v Current Testing v MicroarrayMicroarray SystemsSystems

Donation

Blood grouping NAT testingMicrobiology serology

IT Systems

Release of Blood Donation

RESULTSRESULTS

Donation

Single microarrayplatform

Release of Blood Donation

RESULTSRESULTS

CURRENT CURRENT FutureFuture((MicroarrayMicroarray))

Blood grouping NAT testingMicrobiology serology

Confirmatory Testing

IT Systems

MicroarraysMicroarrays: Benefits: Benefits• Speed / Multiplexing / Multiparameter

High throughput testing – all required tests on one platformExtended assay profile – include all desirable as well as mandatory testsNo confirmatory testing required – replicate testing performed simultaneously

• Reduced CostsSingle Instrument v 3 instruments (capital, maintenance etc)Staff: 1 lab v 3 labs No repeat/confirmatory testingReduced sample requirement

• Patient SafetySingle sampleImproved sensitivity & specificitySingle IT interface

Design of the blood typing Design of the blood typing microarraymicroarray

Immobilised antibody probes

Block NSB

Incubate with test red cell suspension

Scan for fluorescence

Wash the microarray

Addition of test cells

Design of the antibody screening Design of the antibody screening microarraymicroarray

Chip surface

Immobilised antigen*

Plasma/serum added(may contain antibody

to blood group antigens)

Fluorescent detection antibody**

* Immobilised antigen must represent clinically significant blood group antigens e.g. red cells/peptides/alternative source antigen

** Fluorescent detection antibody must bind to clinically significant human blood group antibodies e.g. anti-human IgG/IgM

Design of the DAT Design of the DAT microarraymicroarray

Gold surface

Immobilised antibody probes

Block NSB

Incubate with test red cell suspension

Anti-D (IgG1)

Anti-IgG (Rabbit)

Anti-D (IgG3) Anti-IgG1 Anti-IgG3 Anti-C3

Addition of test cells

Scan for fluorescence

Wash the microarray

Manufacturing ConsiderationsManufacturing Considerations

• Production of Antibodies- monoclonal /polyclonal- purification methods - IgM/IgG- Specificity/best probes

• Production of Antigens- antigen form- purification ?

• Surface chemistry

Manufacturing Considerations

• Process Scale-Up & Validation

• Stability of components (bulk storage, finished product)

• Resources– Facility– Equipment - High throughput printing

• Quality Control

Development and Regulatory Development and Regulatory StrategyStrategy……11• Fully optimise all aspects of comprehensive microarraying

platform• Phased launch to market • Package developed in collaboration • Field trials, validation and verification of platform• Test purchase controlled by software

• Compliance with and approval by regulatory bodies-ISO 13485-European IVD Medical Devices Directive

Development and Regulatory Development and Regulatory StrategyStrategy……22• In the US…

- FDA Center for Devices and Radiological Health is the lead authority for equipment submissions - FDA Center for Biologics Evaluation and Research is lead authority for biological submissions

• Equipment normally cleared first (instrument and software) and is normally submitted by equipment manufacturer.

• However, combination product applications can be accepted• Each case reviewed by FDA and best route agreed• Software validation is likely to be the most complex step in the

validation ( minimised by limited chip options)

• Related guidance listed in July 2007 issue of Transfusion.

Preliminary results Preliminary results –– blood typingblood typing

0

5

10

15

20

25

30

Group O group A1 group B Group A1B

Anti-B (LB2) Anti-A (LA2) Anti-A (ES9) Anti-A(B) (ES15)

Preliminary results Preliminary results –– blood typingblood typing

Probe antibody specificity and concentration

Anti-K 0.5 mg/ml

S/N

0

10

20

30

60

80

100

120

140

160

K heterozygous K homozygous K negative Col 8 Col 10 Col 12 Col 14

K negative

Preliminary results Preliminary results –– antibody antibody screeningscreening

0

0.5

1

1.5

2

2.5

3

3.5

Anti-D Anti-C Anti-E Anti-c Anti-e

R1R1 (CCDDee) R2R2 (DDccEE) rr (ccee)

Red cell membrane fragments immobilised on proprietary surface, antibodies added and detected by addition of anti-human IgG/IgM

Result >1 is positive

Preliminary results Preliminary results –– direct direct antiglobulinantiglobulin testingtesting RR11 r sensitised with IgGr sensitised with IgG33 antianti--DD

Probe antibody specificity and pH

Anti-D K pH 7.0

Monoclonal Anti-IgG3

Rabbit Anti-IgG pH 7.0




Monoclonal Anti-C3

S/N

0

1

2

3

4

5

100

200

300O R1r native O R1r IgG sensitised

Spot replicates = 3, slide replicates = 3

AcknowledgementsAcknowledgements

• Alba Bioscience – Product DevelopmentDr Janine Robb, Linda Knowles

• Scottish National Blood Transfusion ServiceDr Juraj Petrik and his Transfusion Transmitted Infection R&D Group

• University of EdinburghDepartment of Pathway Medicine (formerly SCGTI)

• Scottish Enterprise

Gordon Robb Operations Director

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