Controlled Scanning of Microtiter Plates through the Use of LabVIEW®

Erica Chin

Anton Edmund

Samir Laoui

May 14, 2008

Topics to be Discussed

Background Goals of Project Project Responsibilities Project Timetable Project Results

– Front Panel– Block Diagrams– Test Results

Discussion Recommendations Conclusions

Microtiter Plate

Standard tool in analytical research and clinical diagnostic testing laboratories

Contains 6, 24, 96, 384 or 1536 sample wells arranged in a rectangular matrix

Each well typically holds liquids of up to 200 microliters

Designed to be disposable and usually made of plastic

Use of Microtiter Plate

Antibody-antigen binding can be detected Can detect specific biological, chemical or

physical events in samples stored in these plates

Commercial Microtiter Plate Scanners

High-intensity lamp passes light to microtiter well

Light emitted by reaction is quantified by detector

Detection modes: absorbance, fluorescence, and luminescence

LabVIEW Overview

LabVIEW: Laboratory Virtual Instrumentation Engineering Workbench

LabVIEW is commonly used for data acquisition, instrument control, and industrial automation

One benefit of LabVIEW is the extensive support for accessing instrumentation hardware

APT Stepper Motor Controller

Manufactured by Thorlabs

Can be configured for two or three channels of operation

Excellent low speed performance and positioning stability

APT Configuration Utility

Configure system parameters and configuration settings

Convenient way to make system wide adjustments

Necessary to enter control unit specifications

Can be set for simulation mode for testing purpose

Goals of the Project

Automated scanning– Pre-defined parameters for scanning

Manual scanning– Operator can set process parameters

Data Acquisition

Project Responsibilities

Anton – block diagram for actual scanning Erica – block diagram for direction, moving speed,

acceleration Samir – precision requirement for scanning

Different sections for the reports and presentations were assigned to each group member, but the work of each member was compiled together in a cohesive manner.

Project Timetable

Week Date Plan

5 2/27 Project presentation 1, revise report 1, intial LabVIEW work.

6 3/05 Written report 1, continue initial LabVIEW work.

7 3/12 Work on individual responsibilities for automated scanning and gather block diagrams and front panel for each part of project. Start initial workfor manual scanning.

8 3/19

9 3/26

10 4/02 Complete automated scanning and prepare for project presentation 2, continue work on manual scanning.

11 4/09 Project presentation 2 and prepare report 2.

12 4/16 Written report 2, revise automated scanning block diagrams and front panel and continue working on manual scanning.

13 4/23 Revise manual scanning block diagrams and front panel and start preparing for final presentation and report, debug LabVIEW code.

14 4/30 Debug LabVIEW code.

15 5/08 Debug LabVIEW code, finish preparing for final presentation and report.

16 5/14 Final presentation and report.

Front Panel

User interface that contains controls and indicators Controls

– Knobs– Push buttons– Dials– File selection – Exit button for disaster recovery

Indicators – Graphs– LEDs– Data display

Front Panel

Main VI Components

1. Idle state2. Intensity Map3. Step Motor A4. Step Motor B5. Display of Scanned Well6. Home Position7. Speed and Scan Interval8. Load Position9. Precision

Block Diagram of Main VI

Each of the main VI can be called individually from the front panel even though they are stacked together

Each VI has been built with multi-layer or sub-VI Example: Motor control A

MT sub-VI built with several sub-VIs (get SN, set SN, start MT ctrl) error sub-VI and command sub- VI

Motor References

Pre-set motor references but user can change settings

1. Intensity Map

Intensity Plot

2. Step Motor A

3. Step Motor B

4. Display of Scanned Well

Scanned well will be displayed via graph with its XY coordination

Time stamp will be displayed for scanned time

Home Position

Allows user to reset to initial position of (0,0)

Both controllers need to be initialized before starting the program

Movement Direction

Homeposition

Left or righttop orbottom

Desireddirection

continue orHome

Inputcoordination or

wellsizes

Scanninginterval

Scanning

Reached maximumdirection or want to place

home position

Resethome

NewHome

position

Yes

No

Out putdisplay

Datamanage

ment

Threshold, operatorselection

SpeedControlle

d byoperator

Home Position Block Diagram

Speed and Acceleration

Automated scanning – preset Manual scanning – defined

Set Running State

Load Position

Resume scanning after pausing

Load position and precision can be controlled from front panel

8. Precision

Data Acquisition

Data will be stored at user defined location in text (lvm) format

Test Results

Stages configuration– NTR100E Enc Stage A,

100mm (Serial No 90811662) into Channel 1

– NTR150E Enc Stage B, 150mm (Serial No 90811663) into Channel 2

Manual Scanning

Motor can be initiated by adding correct serial number from the front panel

After a few seconds, sub-VI of motor control will be displayed

This is an ActiveX component of LabVIEW

From this faceplate, speed, scan interval, direction, home, and jog sequence can be controlled

Manual Scanning Results

Useful information through error code panel

No error was observed

Manual scanning was successful

Automatic Scanning

Motors A and B have to be activated or initialized

- It moves its predefined speed with preset

interval

- It works without interruption but with 10003

error code

- Error was send to THORLABS to be

investigated

Automatic Scanning

Initial Position and Optimize Position

LabVIEW was terminated with this error message

These commands are not operating because of lack of hardware component

Discussion

Manual scanning can be controlled via front panel In order to perform automated scanning, two channel

step motors are required Automated scanning was not executed successfully

due to lack of hardware component USB connections are not the ideal set up for high

sensitive scanning ActiveX component for THORLABS in LabVIEW

doesn’t work 100% Similar discrepancy has been observed in Analog

Device’s BLACKFIN communication with LabVIEW

Recommendations

Need to have the all the components prior to LabVIEW programming in order to avoid unnecessary LabVIEW coding and debugging

Initiate both channels for auto-connection Avoid USB connections

Conclusions

Although we do not have appropriate hardware for automated scanning, manual scanning work as desired

By using our program, microtiter plates can be scanned for biosensor applications

Further testing is necessary with all hardware components