Exhibit 21.1

(Revised: December 30, 2011)

Quest Diagnostics Incorporated (DE)
(Incorporated on December 12, 1990 in Delaware; FEIN No. 16-1387862)

Subsidiaries, Joint Ventures and Affiliates

100%	Quest Diagnostics Holdings Incorporated (DE)
	100%	Quest Diagnostics Clinical Laboratories, Inc. (DE)
		(33-l/3%)	CompuNet Clinical Laboratories (OH)
		(44%)	Mid America Clinical Laboratories (IN)
		(51%)	Diagnostic Laboratory of Oklahoma LLC (OK)
100%	Quest Diagnostics Incorporated (MD)
	100%	Diagnostic Reference Services Inc. (MD)
		100%	Pathology Building Partnership (MD) (gen. ptnrshp.)
100%	Quest Diagnostics Incorporated (MI)
100%	Quest Diagnostics Investments Incorporated (DE)
	100%	Quest Diagnostics Finance Incorporated (DE)
100%	Quest Diagnostics LLC (IL)
100%	Quest Diagnostics LLC (MA)
100%	Quest Diagnostics LLC (CT)
100%	Quest Diagnostics Nichols Institute (CA)
100%	Quest Diagnostics of Pennsylvania Inc. (DE)
	51%	Quest Diagnostics Venture LLC (PA)
	53.5%	Associated Clinical Laboratories of Pennsylvania, L.L.C. (PA)
		1%	Associated Clinical Laboratories, L.P. (PA)
	52.97%	Associated Clinical Laboratories, L.P. (PA)
		100%	North Coast General Services, Inc. (PA)
100%	Quest Diagnostics of Puerto Rico, Inc. (PR)
100%	Quest Diagnostics Receivables Inc. (DE)
100%	Quest Diagnostics Ventures LLC (DE)
100%	ADI Holding Company, Inc (DE)
	100%	Athena Diagnostics, Inc. (DE)
100%	American Medical Laboratories, Incorporated (DE)
	100%	Quest Diagnostics Nichols Institute, Inc. (VA)
	100%	Quest Diagnostics Incorporated (NV)
		100%	APL Properties Limited Liability Company (NV)
100%	Celera Corporation (DE)
	100%	Axys Pharmaceuticals, Inc. (DE)
	100%	Berkeley HeartLab, Inc. (CA)
	100%	Celera Diagnostics, LLC (DE)
100%	MetWest Inc. (DE)
	100%	Diagnostic Path Lab, Inc. (TX)
	100%	Quest Diagnostics Provider Network, LLC (CO)
	49%	Sonora Quest Laboratories LLC (AZ)
100%	Enterix Inc. (DE)
	100%	Enterix (Australia) Pty Limited (Australia)
		100%	Enterix Pty Limited (Australia)

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100%	Focus Diagnostics GmbH (Germany)
100%	Focus Diagnostics, Inc. (DE)
100%	HemoCue, Inc. (CA)
100%	QDI Acquisition AB (Sweden)
	100%	POCT Holding AB (Sweden)
		100%	HemoCue Holding AB (Sweden)
			100%	HemoCue AB (Sweden)
				100%	HemoCue Oy (Finland)
			100%	HemoCue GmbH (Germany)
			99.7%	HemoCue AG (Switzerland)
				(remaining 0.3% held in trust for HemoCue Holding AB)
			100%	Biotest Medizintechnik GmbH (Germany)
			100%	HemoCue Diagnostics B.V. (The Netherlands)
			100%	HC Diagnostics, Limited (UK)
			100%	HemoCue South Africa (Pty) Limited (South Africa)
100%	LabOne, Inc. (MO)
	100%	ExamOne World Wide, Inc. (PA)
		100%	ExamOne LLC (DE)
		100%	ExamOne World Wide of NJ, Inc. (NJ)
	100%	LabOne, L.L.C. (KS)
	100%	Central Plains Holdings, Inc. (KS)
	100%	Lab One Canada, Inc. (Ontario)
		100%	ExamOne Canada, Inc. (Ontario)
			100%	Rapid-Med Plus Franchise Corporation (Ontario)
	100%	LabOne of Ohio, Inc. (DE)
100%	C & S Clinical Laboratory, Inc. (NJ)
100%	MedPlus, Inc. (OH)
	100%	Valcor Associates Inc. (PA)
100%	Unilab Corporation (DE)
100%	Nichols Institute Diagnostics (CA)
100%	Nomad Massachusetts, Inc. (MA)
	100%	Laboratorio de Analisis Biomedicos, S.A. (Mexico)
100%	OralDNA Labs, Inc. (DE)
88%	Quest Diagnostics Mexico, S.A. de C.V. (Mexico)
	(12% owned by Nomad)
100%	Quest Diagnostics do Brasil Ltda.(Brazil)
100%	Quest Diagnostics India Private Limited (India)
100%	Quest Diagnostics Ireland Limited (Ireland)
100%	Quest Diagnostics Limited (UK)
	100%	The Pathology Partnership plc (UK)
19.9%	Clinical Genomics Pty Ltd. (Australia)

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100%	AmeriPath Group Holdings, Inc. (DE)
	100%	AmeriPath, Inc. (DE)
		100%	AmeriPath 5.01(a) Corporation (TX)
		100%	AmeriPath Cincinnati, Inc. (OH)
		100%	AmeriPath Cleveland, Inc. (OH)
		100%	AmeriPath Consolidated Labs, Inc. (FL)
		100%	AmeriPath Florida, LLC (DE)
		100%	AmeriPath Indemnity, Ltd. (Cayman Islands)
		100%	AmeriPath Indiana, LLC (IN)
		100%	AmeriPath, LLC (DE)
			100%	AmeriPath Texas, LP (DE)
		100%	AmeriPath Kentucky, Inc. (KY)
		100%	AmeriPath Lubbock 5.01(a) Corporation (TX)
		100%	AmeriPath Lubbock Outpatient 5.01(a) Corporation (TX)
		100%	AmeriPath Marketing USA, Inc (FL)
		100%	AmeriPath Michigan, Inc. (MI)
		100%	AmeriPath Mississippi, Inc. (MS)
		100%	AmeriPath New York, LLC (DE)
		100%	AmeriPath North Carolina, Inc. (NC)
		100%	AmeriPath Ohio, Inc. (DE)
			100%	AmeriPath Youngstown Labs, Inc. (OH)
		100%	AmeriPath PAT 5.01(a) Corporation (TX)
		100%	AmeriPath Pennsylvania, LLC (PA)
		100%	AmeriPath Philadelphia, Inc. (NJ)
		100%	AmeriPath SC, Inc. (SC)
		100%	AmeriPath Texarkana 5.01(a) Corporation (TX)
		100%	AmeriPath Tucson, Inc. (AZ) (fka Jill A. Cohen, M.D., Inc.)
		100%	AmeriPath Wisconsin, LLC (WI)
		100%	AmeriPath Youngstown, Inc. (OH)
		100%	Anatomic Pathology Services, Inc. (OK)
		100%	API No. 2, LLC (DE)
		100%	Arlington Pathology Association 5.01(a) Corporation (TX)
		100%	Consulting Pathologists of Pennsylvania, Inc. (PA)
		100%	Dermatopathology Services, Inc. (AL)
		100%	DFW 5.01(a) Corporation (TX)
		100%	Diagnostic Pathology Management Services, LLC (OK)
		100%	Kailash B. Sharma, M.D., Inc. (GA)
		100%	NAPA 5.01(a) Corporation (TX)
		100%	Nuclear Medicine and Pathology Associates (GA)
		100%	Ocmulgee Medical Pathology Association, Inc. (GA)
		100%	O’Quinn Medical Pathology Association, LLC (GA)
		100%	PCA of Denver, Inc. (TN)
		100%	PCA of Nashville, Inc. (TN)
		100%	Peter G. Klacsmann, M.D., Inc. (GA)
		100%	Sharon G. Daspit, M.D., Inc. (GA)
		100%	Shoals Pathology Associates, Inc. (AL)
		100%	Specialty Laboratories, Inc. (CA)
		100%	Strigen, Inc. (UT)
			100%	Arizona Pathology Group, Inc. (AZ)
			100%	Regional Pathology Consultants, LLC (UT)
			100%	Rocky Mountain Pathology, LLC (UT)
		100%	TID Acquisition Corp. (DE)
		100%	TXAR 5.01(a) Corporation (TX)

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Additional Entities Consolidated for Accounting Purposes

A. Bernard Ackerman, M.D. Dermatopathology, PC (NY)

AmeriPath Consulting Pathology Services, P.A. (NC)

AmeriPath Indianapolis, P.C. (IN)

AmeriPath Institute of Pathology, PC (MI)

AmeriPath Milwaukee, S.C. (WI)

AmeriPath Pittsburgh, P.C. (PA)

Colorado Diagnostic Laboratory, LLC (CO)

Colorado Pathology Consultants, P.C. (CO)

Dermatopathology of Wisconsin, S.C. (WI)

Diagnostic Pathology Services, P.C. (OK)

Institute for Dermatopathology, P.C. (PA)

Kilpatrick Pathology, P.A. (NC)

Rose Pathology Associates, P.C. (CO)

Southwest Diagnostic Laboratories, P.C. (CO)

St. Luke’s Pathology Associates, P.A. (KS)

Tulsa Diagnostics, P.C. (OK)

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