SC 13G

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


SCHEDULE 13G
Under the Securities Exchange Act of 1934



Amendment No.: 


Name of Issuer: I-Stat Corporation 


Title of Class of Securities:  Common Stock


CUSIP Number:  45031210-3



Check the following line if a fee is being paid with this statement X.  (A
fee is not required only if the filing person:  (1) has a previous statement
on file reporting beneficial ownership of more than five percent of the class
of securities described in Item 1; and (2) has filed no amendment subsequent
thereto reporting beneficial ownership of five percent or less of such
class.)(See Rule 13d-7).

*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.: 45031210-3 

1.  NAME OF REPORTING PERSON
         S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
         Janus Capital Corporation
         EIN #84-0765359

2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
         a.   ___
         b.   _X_

3.  SEC USE ONLY

4.  CITIZENSHIP OR PLACE OF ORGANIZATION
         Colorado

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

    5.   SOLE VOTING POWER
              -0-  

    6.   SHARED VOTING POWER
              1,124,600**    
    
    7.   SOLE DISPOSITIVE POWER
              -0-

    8.   SHARED DISPOSITIVE POWER
              1,124,600**

9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         1,124,600**

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
         N/A
         
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
         10.2%**

12. TYPE OF REPORTING PERSON
         IA, CO

**  See Item 4 of this filing
Page 2 of 8 pages

CUSIP No.:  45031210-3

1.  NAME OF REPORTING PERSON
         S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
         Thomas H. Bailey
         SS ####-##-####

2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
         a.   ___
         b.   _X_

3.  SEC USE ONLY   

4.  CITIZENSHIP OR PLACE OF ORGANIZATION
         USA

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

    5.   SOLE VOTING POWER
              -0-

    6.   SHARED VOTING POWER
              1,124,600**

    7.   SOLE DISPOSITIVE POWER
              -0-

    8.   SHARED DISPOSITIVE POWER
              1,124,600**

9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         1,124,600**

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
         N/A

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
         10.2%**

12. TYPE OF REPORTING PERSON
         IN
**  See Item 4 of this filing
Page 3 of 8 pages

Item 1.

    (a). Name of Issuer: I-Stat Corporation ("I-Stat")
    
    (b). Address of Issuer's Principal Executive Offices:

         303 College Road East
         Princeton, NJ 08540

Item 2.

    (a).-(c). Name, Principal Business Address, and Citizenship of Persons
              Filing:

         (1)  Janus Capital Corporation ("Janus Capital")
              100 Fillmore Street, Suite 300
              Denver, Colorado  80206-4923
              Citizenship:  Colorado

         (2)  Thomas H. Bailey ("Mr. Bailey")
              100 Fillmore Street, Suite 300
              Denver, Colorado  80206-4923
              Citizenship:  USA
         
    (d). Title of Class of Securities:  Common Stock 

    (e). CUSIP Number:  45031210-3

Item 3.  

    Janus Capital is an Investment Adviser registered under Section 203 of the
    Investment Advisers Act of 1940.
Page 4 of 8 pages

Item 4.  Ownership

         The information in items 1 and 5 through 11 on the cover pages (pp. 2-
         3) on Schedule 13G is hereby incorporated by reference.

         Janus Capital is a registered investment adviser which furnishes
         investment advice to several investment companies registered under
         Section 8 of the Investment Company Act of 1940 and individual and
         institutional clients (collectively referred to herein as "Managed
         Portfolios").  As a result of its role as investment adviser or sub-
         adviser to the Managed Portfolios, Janus Capital may be deemed to be
         the beneficial owner of the shares of I-Stat Common Stock held by such
         Managed Portfolios.  However, Janus Capital does not have the right to
         receive any dividends from, or the proceeds from the sale of, the
         securities held in the Managed Portfolios and disclaims any ownership
         associated with such rights.

         Mr. Bailey owns approximately 12.2% of Janus Capital.  In addition to
         being a stockholder of Janus Capital, Mr. Bailey serves as President
         and Chairman of the Board of Janus Capital and is filing this joint
         statement with Janus Capital as a result of such stock ownership and
         positions which may be deemed to enable him to exercise control over
         Janus Capital.  Mr. Bailey does not own of record any shares of I-Stat
         Common Stock and he has not engaged in any transaction in I-Stat
         Common Stock.  However, as a result of his position, Mr. Bailey may be
         deemed to have the power to exercise or to direct the exercise of such
         voting and/or dispositive power that Janus Capital may have with
         respect to I-Stat Common Stock held by the Managed Portfolios.  All
         shares reported herein have been acquired by the Managed Portfolios,
         and Mr. Bailey specifically disclaims beneficial ownership over any
         shares of I-Stat Common Stock that he or Janus Capital may be deemed
         to beneficially own.  Furthermore, Mr. Bailey does not have the right
         to receive any dividends from, or the proceeds from the sale of, the
         securities held in the Managed Portfolios and disclaims any ownership
         associated with such rights.
Page 5 of 8 pages

Item 5.  Ownership of Five Percent or Less of a Class

              N/A            

Item 6.  Ownership of More than Five Percent on Behalf of Another Person
    
              Janus Capital's Managed Portfolios, set forth in Item 4 above,
              have the right to receive all dividends from, and the proceeds
              from the sale of, the securities held in their respective
              accounts.
         
              The interest of any one such person does not exceed 5% of the
              class of securities.

Item 7.  Identification and Classification of the Subsidiary Which
         Acquired the Security Being Reported on by the Parent Holding
         Company

              N/A

Item 8.  Identification and Classification of Members of the Group

              N/A

Item 9.  Notice of Dissolution of Group

              N/A

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 purposes or effect.
Page 6 of 8 pages

SIGNATURES

    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.


JANUS CAPITAL CORPORATION

By  /s/  Stephen L. Stieneker                                8/9/95    
   Stephen L. Stieneker, Assistant Vice President              Date


THOMAS H. BAILEY

By  /s/  Stephen L. Stieneker                                8/9/95   
   Stephen L. Stieneker                                        Date

   The Above Signatures
   Under Power of Attorney dated 8/8/95
         
Page 7 of 8 pages
EXHIBIT A



JOINT FILING AGREEMENT


  In accordance with Rule 13d-1(f) under the Securities Exchange Act of 1934,
the persons named below agree to the joint filing on behalf of each of them
of a Statement on Schedule 13G (including amendments thereto) with respect to
the Common Stock of I-Stat Corporation and further agree that this Joint
Filing Agreement be included as an Exhibit to such joint filings.  In
evidence thereof, the undersigned hereby execute this Agreement as of the 9th
day of August, 1995.


            JANUS CAPITAL CORPORATION

            By  /s/  Stephen L. Stieneker           
               Stephen L. Stieneker, Assistant Vice President


            THOMAS H. BAILEY
            
            By  /s/  Stephen L. Stieneker                
               Stephen L. Stieneker

               The Above Signatures
               Under Power of Attorney dated 8/8/95  
               
Page 8 of 8 pages

EX-99.POA

POWER OF ATTORNEY

  The undersigned does hereby appoint Deborah E. Bielicke, Stephen L.
Stieneker and David C. Tucker, and each of them, acting singly, with full
power of substitution, as the true and lawful attorney of the undersigned, to
sign on behalf of the undersigned in respect of the ownership of equity
securities held by the undersigned, Janus Capital Corporation, Janus
Investment Fund and Janus Aspen Series, directly and beneficially, and to be
reported pursuant to Sections 13(d), 13(f), and 13(g) of the Securities and
Exchange Act of 1934, as amended, and to execute joint filing agreements with
respect to such filings

  IN WITNESS WHEREOF, this Power of Attorney, has been executed as of the 8th
day of August, 1995.


                                /s/    Thomas H. Bailey
                                Thomas H. Bailey