Exhibit 10.5

***Text Omitted and Filed Separately

with the Securities and Exchange Commission.

Confidential Treatment Requested

Under 17 C.F.R. Sections 200.80(b)(4)

and 240.24b-2.

AMENDMENT NO. 4 TO

DEVELOPMENT AGREEMENT

FOR PANTHER INSTRUMENT SYSTEM

This Amendment No. 4 (“Amendment No. 4”) is entered into effective as of February 1, 2011 (“Amendment Effective Date”) pursuant to and amending the “Development Agreement for Panther Instrument” (the “Agreement”) between Gen-Probe Incorporated, a Delaware corporation (“Gen-Probe”), and STRATEC Biomedical Systems AG (“STRATEC”) (collectively, “Parties”).

RECITALS

STRATEC and Gen-Probe entered into a Development Agreement for Panther Instrument System having an effective date of 22 November 2006 (“Agreement”), which has been previously amended in writing by the Parties.

The Parties now wish to further amend the Agreement.

NOW, THEREFORE, in consideration of the mutual obligations in this Amendment No. 4, the Parties agree as follows:

TERMS

***Confidential Treatment Requested

IN WITNESS WHEREOF, the Parties have executed this Amendment No. 4 by their duly authorized representatives.

2

EXHIBIT A

Gen-Probe Statement of Work

PANTHER

[…***…] Statement of Work

Revision: A

January 31, 2011

Presented By:

[…***…]

Gen-Probe Incorporated

10210 Genetic Center Drive

San Diego, CA 92131

(858) 410-8000

***Confidential Treatment Requested

1

***Confidential Treatment Requested

2

Stratec Biomedical Systems shall provide services for the prototyping/analysis, design, implementation, and testing of adding […***…] to the PANTHER platform.

This section provides an overview of the tasks to be completed for the prototyping/analysis, design, implementation and validation of […***…] to the PANTHER platform. For a detailed description of the objectives, tasks, and deliverables please see the following documents:

Panther Project Software Development Plan, P10233-0108

Panther Software Architecture Description, P10233-0035

Blood Bank Panther Instrument […***…]SRS, P10233-TBD

Milestone 1 includes project kick off and updating of required project documents including the project management plan, requirements documents, key configuration management, software testing, and defect tracking plans. Milestone 1 is scheduled to be an initial project payment upon signing the project agreement.

***Confidential Treatment Requested

3

Milestone 2 includes […***…]. Milestone 1 is scheduled to be an initial project payment upon signing the project agreement. Milestone 2 is scheduled to be completed […***…].

Milestone 3 includes […***…]. Milestone 3 also includes design review and documentation updates. Milestone 3 includes addressing any issues identified in Milestone 2, executing UIT, informal verification, update design documents, and preparing the software for formal verification and validation. Milestone 3 is scheduled to be feature complete […***…].

This section contains the approach Gen-Probe and Stratec will use to complete the project. Included is a description of the team members, project strategy or development plan, quality processes, schedule, and estimated costs. A more detailed project summary can be found in the Panther Software Development Plan, P10233-0108

***Confidential Treatment Requested

4

This section contains an overview of the estimated proposed project schedule. The schedule provides resources, durations, and task order.

For more details on the project schedule please see […***…] Project Schedule.

Stratec Biomedical will perform the tasks outlined in this work statement on a set Milestone basis. The following table summarizes estimated projected cost required to complete these tasks.

***Confidential Treatment Requested

5

This section lists the assumptions that have been made in preparing this work statement.

***Confidential Treatment Requested

6

See Development Agreement for Panther Instrument System for terms and conditions.

7

EXHIBIT B

STRATEC Proposal

Panther

Instrument System

[...***...] Blood Bank Utilization

Company name and address

Stratec Biomedical Systems AG

Gewerbestr. 37

75217 Birkenfeld

Germany

Contact persons

Bernd M. Steidle

Member, Board of Management, Marketing and Sales

+49 7082 7916 65

b.steidle@stratec-biomedical.de

[...***...]

[...***...]

[...***...]

[...***...]

[...***...]

***Confidential Treatment Requested

1

2

Stratec develops for Gen-Probe a low- to mid-volume instrument named “Panther”, for current and future molecular diagnostic assays.

In accordance with this development Stratec was requested to quote a modification of said instrument for performing current and future blood bank assays (Request for Quotation dated 2009-08-26). In this document the instrument for the blood bank market is named the “Blood Bank Panther”.

The general approach for this project is to [...***...].

With work statement No.1 effective December 03, 2009 the development of the Incremental Change for Blood Screening was amended to the Development Agreement for the Panther Instrument.

In conjunction with the above Stratec was also requested to provide a Proposal for the development of [...***...].

Both instruments shall be considered a Gen-Probe Inc. exclusive product and Gen-Probe will remain the legal manufacturer.

***Confidential Treatment Requested

3

The instrumentation platform for blood bank application is defined in the PRD and the PRD feature summary (attachment A and B of the Request for Quotation).In addition [...***...].

According to these requirements the Blood Bank Panther [...***...].

With this understanding no hardware / module modification is considered in the scope of this development.

However, [...***...].

The responsibilities and development services as defined in the Panther development plan dated 2007-06-13 and related documents remain unchanged, resources and split of tasks between the development sites will be according to the Panther SW development plan dated 2009-09-25.

SW development includes:

The overall cost of the development is USD [...***...].-

Lower level database functions have been planned and implemented under the work statement No. 1 (Incremental Change for Blood Screening), in addition […***…] will be implemented under this development.

***Confidential Treatment Requested

4

As agreed with Gen-Probe the development of the diagnostic Panther has the highest priority.

The team will use its best effort to implement the items needed for the Blood Bank Panther in conjunction with the SW implementation of the other Panther SW lines. However, in case of any scheduling conflict [...***...].

Specific details are provided in the “Multiple Program Software Release Schedule [...***...].

The development and design team remains the same as for the Panther development. The majority of the tasks and responsibilities for the software development will be shared between the different sites according to the SW Development Plan dated 2009-09-25.

Stratec has already added [...***...].

***Confidential Treatment Requested

5