IDH.L Regulatory News (IDH)

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARES

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights are attached:

Immunodiagnostic Systems

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

ü

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to thenotification obligation:

Schroders plc

4. Full name of shareholder(s)  (if different from 3.):

5. Date of the transaction and date onwhich the threshold is crossed orreached:

02.09.12

6. Date on which issuer notified:

03.09.12

7. Threshold(s) that is/are crossed orreached:

Above 10%

8. Notified details:

A: Voting rights attached to shares

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights

Direct

Direct

Indirect

Direct

Indirect

Ordinary

2,756,904

1,939,010

3,502,718

N/A

3,013,718

N/A

10.423

GB00B01YZ052

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate

Exercise/Conversion Period

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date

Exercise/Conversion period

Number of voting rights instrument refers to

% of voting rights

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

3,013,718

10.423

9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable:

Cazenove Capital Management Ltd 8,050 shares 0.028%

Schroder Investment Management Ltd 3,004,319 shares 10.390%

Schroder Investment Management North America Ltd 1,349 shares 0.005%

Proxy Voting:

10. Name of the proxy holder:

11. Number of voting rights proxy holder will ceaseto hold:

12. Date on which proxy holder will cease to holdvoting rights:

13. Additional information:

The shares referred to in section 9 are held in portfolios managed by those firms on a discretionary basis for clients under investment management agreements.

14. Contact name:

Laura Whelan

15. Contact telephone number:

0207 658 6000