Exhibit 10.1

Monogram Biosciences, Inc.

This confirms that I hold the non-qualified stock options to purchase shares of
Monogram Biosciences, Inc. (the “Company”) common stock listed in the following
table which were granted pursuant to the Employment Agreement, dated September
1999, by and between myself and the Company (the “Options”):

 

Option Grant Number

  

Number of Shares Subject to Option

  

Exercise Price per Share

002128

   41,666    $18.84

002129

   41,666    $18.84

I am aware that the Company, Laboratory Corporation of America Holdings
(“Parent”) and Mastiff Acquisition Corp. (“Purchaser”) are concurrently entering
into an Agreement and Plan of Merger (the “Merger Agreement”), and agree and
acknowledge that I will receive substantial benefit from the consummation of the
transactions contemplated by the Merger Agreement.

I agree and acknowledge that, if I do not exercise the Options before the
Effective Time (as defined in the Merger Agreement), the Options will be
cancelled without payment of any consideration and terminated as of the
Effective Time. If the Effective Time does not occur, the Options will not be
cancelled and will remain outstanding in accordance with their terms. I
acknowledge and consent to the treatment of the Options described herein and I
acknowledge that the Company, pursuant to the terms of the Options and as a
result of the agreements and acknowledgments sort forth herein, has the
authority to terminate the Options as of the Effective Time.

[SIGNATURE PAGE FOLLOWS]

 

1.

--------------------------------------------------------------------------------

William D. Young   

/s/ William D. Young

   June 22, 2009 (Signature)    (Date) Monogram Biosciences, Inc.   

/s/ Alfred G. Merriweather

   June 22, 2009 (Signature)    (Date)

 

2.