content: UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
  
  
                                      FORM 8-K
  
  
  
                                   CURRENT REPORT
  
  
         Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
  
  
  
           Date of Report (date of earliest event reported): January 5, 2000
  
  
  
                             MOLECULAR BIOSYSTEMS, INC.
               (Exact name of registrant as specified in its charter)
  
  
  
            Delaware                 1-10546                  36-3078632
  (State of Incorporation)  (Commission File Number)   (I.R.S. Identification No.)
  
  
  
                10030 Barnes Canyon Road, San Diego, California 92121
                      (Address of principal executive offices)
  
  
  
          Registrant's telephone number, including area code: (858) 812-7001
  
  
  
  
  
  
  
  
  <PAGE>
  
  
  
  Item 5.  Other Events
  
  
  Molecular Biosystems to be Quoted on the NASD Over-The-Counter Bulletin Board.
  
  
            Effective January 5, 2000, trading of Molecular Biosystems,  Inc. (the
  "Company") common stock was moved to the NASD Over-The-Counter Bulletin Board. A
  new trading  symbol of "MBIO" was  assigned to the Company by NASD.  The Company
  had  previously  traded on the New York Stock  Exchange  under the  symbol  "MB"
  through the close of business January 4, 2000.
  
  
  
  Item 7.  Financial Statements and Exhibits
  
           10.1              Press release dated December 28, 1999.
  
  
  
  
  
  
  
  
  <PAGE>
  
  
  
  
  
  SIGNATURES
  
  Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
  registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
  undersigned thereunto duly authorized.
  
  
  MOLECULAR BIOSYSTEMS, INC.
  
  
  
  
  /s/ Elizabeth Hougen
  Elizabeth Hougen
  Executive Director, Finance and Chief Financial Officer
  (Principal Financial and Accounting Officer)
  
  
  1/6/00
  
  
  
  
  <PAGE>
  
  
  
                                    Exhibit Index
  
      Exhibit                Description
  
      10.1                   Press release dated December 28, 1999.
  
  
  
  
  
  
  <PAGE>
  
  
  
  
  Exhibit 10.1
  
  
  
  
  Contacts:
  Elizabeth Hougen, Chief Financial Officer (858) 812-7179
  Patricia Sullivan, Manager, Investor Relations (858) 812-7146
  E-Mail: IR@mobi.com
  
  
                           MBI Plans for Listing on NASD's
                           Over-The-Counter Bulletin Board
  
  San Diego, California,  December 28, 1999 - Molecular Biosystems, Inc. announced
  today  that  trading of its common  stock  will  continue  on the New York Stock
  Exchange  until the close of business on Tuesday,  January 4, 2000. The date was
  extended from  December 30, 1999, in order to effectuate an orderly  transition.
  Effective  Wednesday,  January 5, 2000,  MBI's  common  stock is  expected to be
  quoted on NASD's  Over-The-Counter  Bulletin  Board.  A trading  symbol  will be
  assigned when listing commences.
  
  MBI, based in San Diego,  California,  is a world leader in developing  contrast
  agents for diagnostic  imaging.  Its innovative  product,  OPTISON(R),  improves
  diagnosis of heart disease through clearer ultrasound images.
  
  This news release  contains  forward-looking  statements  that involve risks and
  uncertainties.  Among the factors that could  result in a  materially  different
  outcome  are:  MBI's  failure to be quoted on NASD's  Over-The-Counter  Bulletin
  Board and other risk factors  reported  from time to time in MBI's  filings with
  the Securities and Exchange Commission.
  
         For More Information on Molecular Biosystems by Fax, Dial 888-329-4007,
                         or Visit its Web site: www.mobi.com
metadata_documents: [{"type": "8-K", "sequence": "1", "description": "MOLECULAR BIOSYSTEMS MOVES TO OTC BULLETIN BOARD", "secsgml_size_bytes": 3608}]
metadata_filer: {"company-data": {"conformed-name": "MOLECULAR BIOSYSTEMS INC", "cik": "0000719598", "assigned-sic": "2835", "irs-number": "363078632", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-10546", "film-number": "504904"}, "business-address": {"street1": "10030 BARNES CANYON RD", "city": "SAN DIEGO", "state": "CA", "zip": "92121-2789", "phone": "8588127001"}, "mail-address": {"street1": "10030 BARNES CANYON ROAD", "city": "SAN DIEGO", "state": "CA", "zip": "92121"}}
text: UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                      FORM 8-K
  
                                   CURRENT REPORT
  
         Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
  
           Date of Report (date of earliest event reported): January 5, 2000
  
                             MOLECULAR BIOSYSTEMS, INC.
               (Exact name of registrant as specified in its charter)
  
            Delaware                 1-10546                  36-3078632
  (State of Incorporation)  (Commission File Number)   (I.R.S. Identification No.)
  
                10030 Barnes Canyon Road, San Diego, California 92121
                      (Address of principal executive offices)
  
          Registrant's telephone number, including area code: (858) 812-7001
  Item 5.  Other Events
  
  Molecular Biosystems to be Quoted on the NASD Over-The-Counter Bulletin Board.
  
            Effective January 5, 2000, trading of Molecular Biosystems,  Inc. (the
  "Company") common stock was moved to the NASD Over-The-Counter Bulletin Board. A
  new trading  symbol of "MBIO" was  assigned to the Company by NASD.  The Company
  had  previously  traded on the New York Stock  Exchange  under the  symbol  "MB"
  through the close of business January 4, 2000.
  
  Item 7.  Financial Statements and Exhibits
  
           10.1              Press release dated December 28, 1999.
  SIGNATURES
  
  Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
  registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
  undersigned thereunto duly authorized.
  
  MOLECULAR BIOSYSTEMS, INC.
  
  /s/ Elizabeth Hougen
  Elizabeth Hougen
  Executive Director, Finance and Chief Financial Officer
  (Principal Financial and Accounting Officer)
  
  1/6/00
  Exhibit Index
  
      Exhibit                Description
  
      10.1                   Press release dated December 28, 1999.
  Exhibit 10.1
  
  Contacts:
  Elizabeth Hougen, Chief Financial Officer (858) 812-7179
  Patricia Sullivan, Manager, Investor Relations (858) 812-7146
  E-Mail: IR@mobi.com
  
                           MBI Plans for Listing on NASD's
                           Over-The-Counter Bulletin Board
  
  San Diego, California,  December 28, 1999 - Molecular Biosystems, Inc. announced
  today  that  trading of its common  stock  will  continue  on the New York Stock
  Exchange  until the close of business on Tuesday,  January 4, 2000. The date was
  extended from  December 30, 1999, in order to effectuate an orderly  transition.
  Effective  Wednesday,  January 5, 2000,  MBI's  common  stock is  expected to be
  quoted on NASD's  Over-The-Counter  Bulletin  Board.  A trading  symbol  will be
  assigned when listing commences.
  
  MBI, based in San Diego,  California,  is a world leader in developing  contrast
  agents for diagnostic  imaging.  Its innovative  product,  OPTISON(R),  improves
  diagnosis of heart disease through clearer ultrasound images.
  
  This news release  contains  forward-looking  statements  that involve risks and
  uncertainties.  Among the factors that could  result in a  materially  different
  outcome  are:  MBI's  failure to be quoted on NASD's  Over-The-Counter  Bulletin
  Board and other risk factors  reported  from time to time in MBI's  filings with
  the Securities and Exchange Commission.
  
         For More Information on Molecular Biosystems by Fax, Dial 888-329-4007,
                         or Visit its Web site: www.mobi.com