MICRO CONTROLLER BASED ELISA READER

ByP. Mahender Babu(10PQ1A0474)

G.Shyam Kumar(10PQ1A04A2)

OVERVIEW

• Objective

• Introduction

• Principle of Operation

• Description of the System

• Block Diagram

• Interfacing Stepper Motor with Microcontroller

• Elisa data from Three different patients

• Elisa Reader

• Applications of Elisa Reader

• Scope of Development

IntroductionWhy known as ......ELISA?

ELISA is the abbreviation of Enzyme-Linked Immuno Sorbent Assay

• Antigen of interest is absorbed on to plastic surface (“sorbent”)

• Antigen is recognised by specific antibody (“immuno”)

• This antibody is recognised by second antibody (“immuno”) which has enzyme attached (“enzyme- linked”)

• Substrate reacts with enzyme to produce product, usually coloured.

ANTIGEN (Ag)

• Any molecule that induces production of antibodies When introduced in the body of an animal is called antigen.

e.g. bacteria, viruses

ANTIBODY ( Ab)

• Proteins produced by the immune system which help defend against antigens.

e.g. lymphocytes

SYMBOL FOR ANTIBODY

SYMBOL FOR ANTIGEN

PRINCIPLE OF OPERATION

• It is based on the principle of Spectrophotometry

• A spectrophotometer is an instrument that measures the amount of light absorbed by a sample.

DESCRIPTION OF THE SYSTEM

• Elisa Plate-Flat or bottomed 96 wells micro plate

• Light source: tungsten - halogen lamp

• Optical system: Grating Monochromator

• Optical Fibre

• MicroControllers-8051F124,ATMEL 89C52

• DRIVER IC 5804

• Detector: Photo diode

• Display: 24*2 line alphanumeric LCD

• Power supply: 230+-10% Ac, 50 Hz

• 2 Stepper Motors

Elisa Plate•The equipment of ELISA consists of a micro-plate which consists 96 wells. The wells are arranged in the form of 8 rows and 12 columns. By this arrangement we can detect 96 samples at a time.

•Marked on one side alphabetically

•Numerically on the other side

Tungsten Lamp

This lamp consists of a tungsten filament enclosed ina glass envelope, with a wavelength range of about330 to 900 nm, are used for the visible region. It haslong life about 1200h.

MonochromatorAccepts polychromatic input light from a lamp and outputs monochromatic light.

Optical Fibers

• Fibre optics (optical fibers) are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances.

It has the following parts:

• Core - Thin glass center of the fiber where the light travels

• Cladding - Outer optical material surrounding the core that reflects the light back into the core

• Buffer coating - Plastic coating that protects the fiber from damage and moisture

Micro Controller 8051F124Thin Quad Flat Pack (TQFP)

MICROCONTROLLER C8051F124 Specifications:

• Core Processor: 8051

• Program Memory Size: l28k bytes of in-system programmable FLASH memory

• RAM Size: 8448 (8k + 256) bytes of on-chip RAM

• Number of I /O: 64

• Package / Case: 100-TQFP

• Speed: 50MHz

• Oscillator Type: Internal

• Packaging: Tray

• Program Memory Type: FLASH ; EEPROM

• Data Converters: A/D 8x8b, 8x12b; D/A 2x12b

• Operating Temperature: -40°C ~ 85°C

• Connectivity: EBI/EMI, SMBus (2-Wire/I²C), SPI, UART/USART

• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT

• Voltage - Supply (Vcc/Vdd): 2.7 V ~ 3.6 V

Microcontroller ATMEL AT89C52

• Compatible with MCS-5l Products • 8k bytes of In-System Reprogrammable Flash Memory .• Endurance: 1,000 Write/Erase Cycles • Fully Static Operation: 0 Hz to 24 MHz• Three-level Program Memory Lock. • 256*8 -bit Internal RAM. • 32 Programmable I/O Lines . • Three 16-bit Timer/Counters . • Eight Interrupt Sources . • Programmable Serial Channel.• Low-power Idle and Power-down Mode

DRIVER IC 5804

• 1.5 A Maximum Output Current

• 35 V Output Sustaining Voltage

• Wave-Drive, Two-Phase, and half-Step Drive Formats

• Internal Clamp Diodes

• Output Enable and Direction Control

• Power-ON Reset

• internal Thermal Shutdown Circuitry

Silicon PIN Photodiodes

Photovoltaic V-Series

• Designed for low-noise, D.C. to medium bandwidth applications. Active areas range from .31mm² to 100mm². Applications include: low light level measurements, particle counting, chemical and analytical measurement and detection.

Display: 24*2 line alphanumeric LCD

Elisa data from Three different patients

PositiveControl

Patient A Patient B Patient C

1.689 0.055 0.412 1.999

ELISA READER

Instrumentation Division (E.C.I.L)

APPLICATIONS OF ELISA READER

• Screening donated blood for evidence of viral contamination by

– Presence of HIV antibodies in blood.

– Mycobacterial antibodies in tuberculosis.

• Screening of viral and bacterial Infections

• Detection of Hepatitis B markers in serum.

• Detection of rotavirus in faeces.

• Measuring hormone levels

– HCG (as a test for pregnancy)

– LH (determining the time of ovulation)

– TSH, T3 and T4 (for thyroid function)

SCOPE FOR DEVELOPMENT:

• Using proper interface devices it can be controlled through a computer.

DISADVANTAGE:

• Requires spectrophotometric plate reader.

REFERENCES

• www.techno2know.com

• http://www.silabs.com/

• www.tecan.com

• www.maxima.in.com

Any Queries ?