**Exhibit 31.1**

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**Certification of Principal Executive OfficerPursuant to Exchange Act Rule 13a-14(a)/15d-14(a)As Adopted Pursuant to Section 302 of The Sarbanes-Oxley Act of 2002**

 

I, Kevin J. Ryan, certify that:

 

1.               Ihave reviewed this quarterly report on Form 10-Q of Large Scale BiologyCorporation;

 

2.               Based on my knowledge, this report does notcontain any untrue statement of a material fact or omit to state a materialfact necessary to make the statements made, in light of the circumstances underwhich such statements were made, not misleading with respect to the periodcovered by this report;

 

3.               Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the Registrant as of, andfor, the periods presented in this report;

 

4.               The Registrant’sother certifying officer(s) and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) for the Registrant and have:

 

a)              designed suchdisclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the Registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

 

b)             evaluated theeffectiveness of the Registrant’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by thisreport based on such evaluation; and

 

c)              disclosed in thisreport any change in the Registrant’s internal control over financial reportingthat occurred during the Registrant’s second fiscal quarter that has materiallyaffected, or is reasonably likely to materially affect, the Registrant’sinternal control over financial reporting; and

 

5.               The Registrant’sother certifying officer(s) and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the Registrant’sauditors and the audit committee of the Registrant’s board of directors (orpersons performing the equivalent functions):

 

a)              all significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adverselyaffect the Registrant’s ability to record, process, summarize and reportfinancial information; and

 

b)             anyfraud, whether or not material, that involves management or other employees whohave a significant role in the Registrant’s internal control over financialreporting.

 

 
| **Date:   August 15, 2005** | **/s/ Kevin J. Ryan**                     | ** ** |
|--------------------------------------------|-------------------------------------------|------------|
| ** **                                 | **Kevin J. Ryan**                         |
| ** **                                 | **President** and Chief Executive Officer |

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