Exhibit 21.1

Subsidiaries of Hologic	Jurisdiction of Incorporation or Organization
AEG Elektrofotografie GmbH	Germany
AEG Photoconductor Corporation	Delaware
BioLucent, LLC	Delaware
Cruiser, Inc.	Delaware
Hologic (Australia) PTY Ltd.	Australia
Hologic Canada, Ltd	Canada
Cytyc Cayman Limited	Cayman Islands
Cytyc Corporation	Delaware
Cytyc Development Company, LLC	Delaware
Hologic Benelux B.V.	Netherlands
Hologic Europe Middle East and Africa, S.A.	Switzerland
Hologic France, SARL	France
Hologic Deutschland GmbH	Germany
Hologic Asia Pacific Limited	Hong Kong
Hologic Iberia, S.L.	Spain
Cytyc Interim, Inc.	Delaware
Cytyc International, Inc.	Delaware
Hologic Italia S.r.l.	Italy
Cytyc Limited Liability Company	Delaware
Cytyc Prenatal Products Corp.	Delaware
Cytyc Securities Corporation	Massachusetts
Hologic Suisse SA	Switzerland
Cytyc Surgical Products II, Limited Partnership.	Massachusetts
Cytyc Surgical Products III, Inc.	Delaware
Cytyc Surgical Products Limited Partnership	Massachusetts
Direct Radiography Corp.	Delaware
Hologic Asia Limited	Hong Kong
Hologic España S.A.	Spain
Hologic N.V.	Belgium
Hologic France SA	France
Hologic International Holdings B.V.	Netherlands
Hologic Investment Corp.	Massachusetts
Hologic Limited Partnership	Massachusetts
Hologic Surgical Products Costa Rica S.A.	Costa Rica
Hologic (UK) Limited	England and Wales
Interlace Medical, Inc.	Delaware
R2 Technology Canada Inc.	Ontario
SST Merger Corp.	Delaware
Sentinelle Medical Inc.	Canada
Sentinelle Medical USA Inc.	Nevada
Suros Surgical Systems, Inc.	Delaware
Third Wave Technologies, Inc.	Delaware
Third Wave Agbio Inc.	Delaware
Third Wave Japan, Inc.	Japan
Navigation Three Limited	Hong Kong
TCT International Co., Ltd.	British Virgin Islands

Subsidiaries of Hologic	Jurisdiction of Incorporation or Organization
Beijing Century Aikang Technology Co., Ltd.	China
TCT Medical (Beijing) Clinical Test Institute	China
Huaxia Likang (Beijing) Technology Co., Ltd.	China
Hangzhou Zuanbai Technology Co., Ltd	China
Beijing TCT Jinbai Technology Co., Ltd.	China
Mingwood Biotechnology Co., Ltd.	China
Century Likang (Beijing) Co., Ltd.	China
Beijing TCT Medical Technology Co., Ltd.	China
Jiangsu Kang Ke Medical Devices Co., Ltd.	China
Zheng Zhou Yong Run Medical Devices Co., Ltd.	China
Beijing Healthcome Technology Company, Ltd.	China