SECURITIES AND EXCHANGE
                             WASHINGTON, D.C. 20549

                                   FORM 12b-25

                                                Commission file number 0-230 17

                           NOTIFICATION OF LATE FILING

(Check One): _ Form 10-K _ Form 20-F _ Form 11-K   x Form 10-QSB  _ Form N-SAR


For Period Ended: June 30, 2002
                  -------------

__ Transition Report on Form 10-K           __  Transition Report on Form 10-Q
__ Transition Report on Form 20-F           __  Transition Report on Form N-SAR
__ Transition Report on Form 11-K

           For the Transition Period Ended:
                                           -----------------------------------
           Read attached instruction sheet before preparing form.
           Please print or type.

           Nothing in this form shall be construed to imply that the Commission
has verified any information contained herein.

           If the notification relates to a portion of the filing checked
above, identify the item(s) to which the notification relates:        N/A
                                                               ----------------

                                     PART I
                             REGISTRANT INFORMATION

           Full Name of Registrant:       Sontra Medical Corporation
                                          ------------------------------

           Former Name if Applicable:     ChoiceTel Communications, Inc.
                                          ------------------------------

           Address of principal executive office (Street and Number):

                                                    58 Charles Street

           City, State and Zip Code:      Cambridge, Massachusetts  02141
                                          --------------------------------

                                     PART II
                            RULES 12b-25 (b) AND (c)

           If the subject report could not be filed without unreasonable effort
or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the
following should be completed. (Check box if appropriate.)


            (a)        The reasons described in reasonable detail in Part III
                       of this form could not be eliminated without
                       unreasonable effort or expense;
            (b)        The subject annual report, semi-annual report, transition
                       report on Form 10-K, 20-F, 11-K or Form N-SAR, or portion
                       thereof will be filed on or before the 15th calendar day
                       following the prescribed due date; or the subject
                       quarterly report or transition report on Form 10-Q, or
                       portion thereof will be filed on or before the fifth
                       calendar day following the prescribed due date; and
            (c)        The accountant's statement or other exhibit required by
                       Rule 12b-25(c) has been attached if applicable.



                                    PART III
                                    NARRATIVE

           State below in reasonable detail the reasons why Forms 10-K, 20-F,
11-K, 10-Q, N-SAR or the transition report portion thereof could not be filed
within the prescribed time period. (Attach Extra Sheets if Needed.)

           As a result of the consummation of the business combination on June
           20, 2002, by and among the registrant and Sontra Medical, Inc.
           (Sontra), whereby the registrant began operating in Sontra's line of
           business, the registrant needs more time to the complete its
           consolidated financial statements for the quarter ended June 30, 2002
           because the registrant's review process with its independent public
           accountant could not be completed within the prescribed time period
           without the registrant incurring unreasonable effort or expense.
           Therefore, the registrant could not file its Form 10-QSB for the
           quarter ended June 30, 2002 within the prescribed time period without
           incurring unreasonable effort or expense. The registrant expects to
           be able to file such Form 10-QSB within the additional time allowed
           for such filing pursuant to Rule 12b-25 of the rules and regulations
           promulgated by the Securities and Exchange Commission under the
           Securities and Exchange Act of 1934, as amended.

                                     PART IV
                                OTHER INFORMATION

           (1) Name and telephone number of person to contact in regard to this
               notification.

           Thomas W. Davison          617                 494-5337
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                      (Name)       (Area Code)       (Telephone Number)

           (2) Have all other periodic reports required under Section 13 or
15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment
Company Act of 1940 during the preceding 12 months or for such shorter period
that the registrant was required to file such report(s) been filed? If answer is
not, identify report(s).
                                          x Yes        No

           (3) Is it anticipated that any significant change in results of
operations from the corresponding period for the last fiscal year will be
reflected by the earnings statements to be included in the subject report or
portion thereof?
                                          x Yes        No

           If so: attach an explanation of the anticipated change, both
narratively and quantitatively, and, if appropriate, state the reasons why a
reasonable estimate of the results cannot be made.

           In connection with the consummation of the business combination
           between the registrant and Sontra Medical, Inc. (Sontra), the results
           for the quarter reflect the application of reverse merger accounting
           principles under generally accepted accounting principles which
           provide that the historical results of Sontra's business be treated
           as the historical results of the combined entity. Accordingly, the
           results for the quarter reflect three months of Sontra's business
           together with ten days of the registrant's operations, which occurred
           after the transaction closed on June 20, 2002. . The registrant has
           no revenues for the quarter ended June 30, 2002, compared with
           revenues of $4,886 for the corresponding period a year earlier. The
           registrant's net loss for the quarter ended June 30, 2002 is
           approximately $750,000 compared with net income of $1,083,230 for the
           same period last year


                           Sontra Medical Corporation
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                  (Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned
hereunto duly authorized.


Date:  August  14,  2002        By  /s/ Thomas W. Davision
       -----------------            ---------------------------
                                        Thomas W. Davision
                                        President and Chief Executive Officer