Common Contracts

QUEST DIAGNOSTICS INCORPORATED (a Delaware corporation) $300,000,000 3.200% Senior Notes Due 2016 $550,000,000 4.700% Senior Notes Due 2021 $200,000,000 5.750% Senior Notes Due 2040 $200,000,000 Floating Rate Senior Notes Due 2014 UNDERWRITING AGREEMENT

Underwriting Agreement • March 25th, 2011 • Quest Diagnostics Inc • Services-medical laboratories • New York

• Contract Type
  Underwriting Agreement
• Filed
  March 25th, 2011
• Company
  Quest Diagnostics Inc
• Industry
  Services-medical laboratories
• Jurisdiction
  New York

Quest Diagnostics Incorporated, a Delaware corporation (the “Company”), and each of the Guarantors listed on Schedule D hereto (the “Guarantors”), confirm their respective agreements with Morgan Stanley & Co. Incorporated (“Morgan Stanley”), Goldman, Sachs & Co. (“Goldman Sachs”), RBS Securities Inc. (“RBS”), J.P. Morgan Securities LLC (“J.P. Morgan”) and Wells Fargo Securities, LLC (“Wells Fargo”) (collectively the “Joint Book-Running Managers”) and each of the other Underwriters named in Schedule A hereto (collectively, the “Underwriters”, which term shall also include any underwriter substituted as hereinafter provided in Section 11 hereof), for whom Morgan Stanley, Goldman Sachs, RBS, J.P. Morgan and Wells Fargo are acting as representatives (in such capacity, the “Representatives”), with respect to (i) the issue and sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective principal amounts set forth in said Schedule A of $300,00

QUEST DIAGNOSTICS INCORPORATED (a Delaware corporation) $500,000,000 4.750% Senior Notes Due 2020 $250,000,000 5.750% Senior Notes Due 2040 UNDERWRITING AGREEMENT Dated: November 12, 2009

Underwriting Agreement • November 16th, 2009 • Quest Diagnostics Inc • Services-medical laboratories • New York

• Contract Type
  Underwriting Agreement
• Filed
  November 16th, 2009
• Company
  Quest Diagnostics Inc
• Industry
  Services-medical laboratories
• Jurisdiction
  New York

Quest Diagnostics Incorporated, a Delaware corporation (the “Company”), and each of the Guarantors listed on Schedule D hereto (the “Guarantors”), confirm their respective agreements with Banc of America Securities LLC (“Banc of America”), Morgan Stanley & Co. Incorporated (“Morgan Stanley”), RBS Securities Inc. (“RBS”) and Wells Fargo Securities, LLC (“Wells Fargo Securities”) (collectively the “Joint Book-Running Managers”) and each of the other Underwriters named in Schedule A hereto (collectively, the “Underwriters”, which term shall also include any Underwriter substituted as hereinafter provided in Section 11 hereof), for whom Banc of America, Morgan Stanley, RBS and Wells Fargo Securities are acting as representatives (in such capacity, the “Representatives”), with respect to (i) the issue and sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective principal amounts set forth in said Schedule A of $500,000,000 aggregate princ