SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                                 SCHEDULE 13G


                                 (Rule 13d-102)


             INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2


                   Under the Securities Exchange Act of 1934
                               (Amendment No.)

                                 PERKIN ELMER CORP
              -----------------------------------------------------
                                (Name of Issuer)
                                  Common Stock
              -----------------------------------------------------
                         (Title of Class of Securities)

                                    714046109
             -----------------------------------------------------
                                 (CUSIP Number)



Check the following box if a fee is being paid with this statement [ ].


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*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

CUSIP No. 714046109 13G Page 2 of 6 Pages - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON(S) S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON(S) Morgan Stanley Dean Witter & Co. IRS # 39-314-5972 - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ] (b) [ ] - -------------------------------------------------------------------------------- 3. SEC USE ONLY - -------------------------------------------------------------------------------- 4. CITIZENSHIP OR PLACE OF ORGANIZATION The state of organization is Delaware. - -------------------------------------------------------------------------------- NUMBER OF 5. SOLE VOTING POWER SHARES 0 BENEFICIALLY -------------------------------------------------------------- OWNED BY 6. SHARED VOTING POWER EACH 2,765,486 REPORTING -------------------------------------------------------------- PERSON 7. SOLE DISPOSITIVE POWER WITH 0 -------------------------------------------------------------- 8. SHARED DISPOSITIVE POWER 2,775,938 - -------------------------------------------------------------------------------- 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,775,938 - -------------------------------------------------------------------------------- 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* - -------------------------------------------------------------------------------- 11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 5.5% - -------------------------------------------------------------------------------- 12. TYPE OF REPORTING PERSON* IA, CO - -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT!

CUSIP No. 714046109 13G Page 3 of 6 Pages Item 1. (a) Name of Issuer: PERKIN ELMER CORP -------------------------------------------------------------- (b) Address of Issuer's Principal Executive Offices: 45 WILLIAM ST WELLESLEY MA 02481 --------------------------------------------------------------- Item 2. (a) Name of Person Filing: Morgan Stanley Dean Witter & Co. -------------------------------------------------------------- (b) Address of Principal Business Office, or if None, Residence: 1585 Broadway New York, New York 10036 -------------------------------------------------------------- (c) Citizenship: Incorporated by reference to Item 4 of the cover page pertaining to each reporting person. ------------------------------------------------- (d) Title of Class of Securities: Common Stock -------------------------------------------------------------- (e) CUSIP Number: 714046109 ------------------------------------------------- Item 3. (a) Morgan Stanley Dean Witter & Co. is (e) an Investment Adviser registered under Section 203 of the Investment Advisers Act of 1940.

CUSIP No. 714046109 13-G Page 4 of 6 Pages Item 4. Ownership. Incorporated by reference to Items (5) - (9) and (11) of the cover page. Item 5. Ownership of Five Percent or Less of a Class. Inapplicable Item 6. Ownership of More Than Five Percent on Behalf of Another Person. Accounts managed on a discretionary basis by Morgan Stanley Dean Witter & Co. are known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of such securities. No such account holds more than 5 percent of the class. Item 7. Identification and Classification of the Subsidiary which Acquired the Security Being Reported on By the Parent Holding Company. Item 8. Identification and Classification of Members of the Group. Item 9. Notice of Dissolution of Group. Item 10. Certification. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purpose or effect.

CUSIP No. 714046109 13-G Page 5 of 6 Pages Signature. After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Date: January 31, 2001 Signature: /s/ Dennine Bullard ----------------------------------------------------------------- Name/Title Dennine Bullard / Morgan Stanley & Co. Incorporated ----------------------------------------------------------------- MORGAN STANLEY DEAN WITTER & CO. INDEX TO EXHIBITS PAGE ----------------- ---- EXHIBIT 1 Secretary's Certificate Authorizing Dennine Bullard 6 to Sign on behalf of Morgan Stanley Dean Witter & Co. * Attention. Intentional misstatements or omissions of fact constitute federal criminal violations (see 18 U.S.C. 1001). (022597DTI)

Page 6 of 6 Pages EXHIBIT 1 ------------------ MORGAN STANLEY, DEAN WITTER, DISCOVER & CO. SECRETARY'S CERTIFICATE I, Charlene R. Herzer, a duly elected and Assistant Secretary of Morgan Stanley Dean Witter & Co., a corporation organized and existing under the laws of the State of Delaware (the "Corporation"), certify that Stuart J.M. Breslow, Robert G. Koppenol and Dennine Bullard are authorized to sign reports to be filed under Sections 13 and 16 of the Securities Exchange Act of 1934 (the "Act") pursuant to the following: (1) On May 31, 1997, the Board of Directors of the Corporation granted authority to Stuart J.M. Breslow and Robert G. Koppenol to sign reports to be filed under Sections 13 and 16 of the Act on behalf of the Corporation. (2) On February 23, 2000, Donald G. Kempf, Jr., the Executive Vice President, Chief Legal Officer and Secretary of the Corporation, delegated authority to Dennine Bullard to sign reports to be filed under Sections 13 and 16 of the Act on behalf of the Corporation. Pursuant to Section 7.01 of the Bylaws of the Corporation and resolutions approved by the Board of Directors of the Corporation on September 25, 1998, the Chief Legal Officer is authorized to enter into agreements and other instruments on behalf of the Corporation and may delegate such powers to others under his jurisdiction. IN WITNESS WHEREOF, I have hereunto set my name and affixed the seal of the Corporation as of the 1st day of March, 2000. ______________________________ Charlene R. Herzer Assistant Secretary