Exhibit 31.1
 Certification of Principal Executive Officer Pursuant to Securities Exchange Act Rule 13a-14(a)
  1.
    
    I have reviewed this annual report on Form 10-K of Meridian Bioscience, Inc.;2.
    
    Based on my knowledge, this report does not contain any untrue statement of a material
fact or omit to state a material fact necessary to make the statements made, in
light of the circumstances under which such statements were made, not misleading with
respect to the period covered by this report;3.
    
    Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects the
financial condition, results of operations and cash flows of the registrant as of,
and for, the periods presented in this report;4.
    
    The registrants other certifying officer(s) and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial
reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the
registrant and have:
 a)
    
    Designed such disclosure controls and procedures, or caused such disclosure
controls and procedures to be designed under our supervision, to ensure that
material information relating to the registrant, including its consolidated
subsidiaries, is made known to us by others within those entities, particularly during
the period in which this report is being prepared;b)
    
    Designed such internal controls over financial reporting, or caused such internal
control over financial reporting to be designed under our supervision, to
provide reasonable assurance regarding the reliability of financial reporting and
the preparation of the financial statements for external purposes in accordance with
generally accepted accounting principles;c)
    
    Evaluated the effectiveness of the registrants disclosure controls and procedures
and presented in this report our conclusions about the effectiveness of the
disclosure controls and procedures, as of the end of the period covered by this
report based on such evaluation; andd)
    
    Disclosed in this report any change in the registrants internal control
over financial reporting that occurred during the registrants fourth fiscal quarter
that has materially affected, or is reasonably likely to materially affect, the
registrants internal control over financial reporting; and
 5.
    
    The registrants other certifying officer(s) and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
registrants auditors and the audit committee of the registrants board of
directors (or persons performing the equivalent functions):
 a)
    
    All significant deficiencies and material weaknesses in the design or operation of
internal control over financial reporting which are reasonably likely to adversely
affect the registrants ability to record, process, summarize and report financial
information; andb)
    
    Any fraud, whether or not material, that involves management or
other employees who have a significant role in the registrants internal control
over financial reporting.
  /s/ John A. Kraeutler