cobas c 303 analytical unit 09793194001Recalls & reported problems

Summary

The FDA's MAUDE database contains 96 adverse event reports that list this exact device (DI 07613336220153), received between Aug 30, 2023 and Sep 10, 2026 — classified as 2 injuries, 94 malfunctions.

The most frequently reported specific device problem is “High Test Results” (54 reports).

Reports come from manufacturers, hospitals and patients and are not verified by the FDA. A report does not prove the device caused the event, and counts can't be used to compare devices or estimate failure rates. What reports can and can't tell you · How this data works · Data updated Oct 18, 2026.

Most reported problems

Recent adverse event reports

The 25 most recent of 96 reports, in the reporter's own words as published by the FDA.

• MalfunctionSep 10, 2026Mechanical Problem; Non Reproducible Results

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50717075 ↗
• MalfunctionAug 4, 2026Mechanical Problem; Non Reproducible Results

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50131187 ↗
• MalfunctionAug 4, 2026Low Test Results

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50127606 ↗
• MalfunctionJun 10, 2026Incorrect, Inadequate or Imprecise Result or Readings; High Test Results

  THE INITIAL REPORTER STATED THEY RECEIVED DISCREPANT RESULTS FOR TWO PATIENT SAMPLES TESTED WITH THE SODIUM ELECTRODE ON A COBAS C 303 ANALYTICAL UNIT. A DOCTOR QUESTIONED THE INITIAL RESULTS. THE INITIAL RESULTS ALSO FAILED LABORATORY DELTA CHECKS. THE SAMPLES WERE REPEATED ON A SECOND ANALYZER AND THESE VALUES WERE DEEMED CORRECT. THE FIRST PATIENT SAMPLE INITIALLY RESULTED IN A SODIUM VALUE OF 139.5 MMOL/L AND IT REPEATED AS 129.9 MMOL/L. THE SECOND PATIENT SAMPLE INITIALLY RESULTED IN A SODIUM VALUE OF 162.2 MMOL/L AND IT REPEATED AS 152.8 MMOL/L.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25456473 ↗
• MalfunctionJun 5, 2026Incorrect, Inadequate or Imprecise Result or Readings

  WE RECEIVED AN ALLEGATION OF QUESTIONABLE SODIUM ELECTRODE RESULTS FOR 1 PATIENT SAMPLE TESTED ON A COBAS C 303 ANALYTICAL UNIT. INITIAL RESULT: 129 MMOL/L. THE PROVIDER QUESTIONED THE INITIAL RESULT, PROMPTING THE REPEAT OF THE SAMPLE. REPEAT RESULT: 135 MMOL/L. THE REPEAT RESULT WAS DEEMED TO BE CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25408223 ↗
• MalfunctionJun 1, 2026High Test Results

  THE INITIAL REPORTER COMPLAINED OF CALIBRATION ISSUES, QC ISSUES, AND DISCREPANT RESULTS FOR 2 PATIENT SAMPLES TESTED FOR ELECTRODE, SODIUM (NA) ON A COBAS PURE SAMPLE SUPPLY UNIT. PATIENT 1 INITIAL RESULT WAS 153 MMOL/L. THE REPEAT RESULT WAS 146 MMOL/L. PATIENT 2 INITIAL RESULT WAS 149 MMOL/L. THE REPEAT RESULT WAS 143 MMOL/L.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25353891 ↗
• MalfunctionMay 22, 2026Incorrect, Inadequate or Imprecise Result or Readings; High Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE TINA-QUANT HEMOGLOBIN A1CDX GEN.3 ASSAY RESULT FOR 5 PATIENT SAMPLES TESTED ON THE COBAS C 303 ANALYTICAL UNIT. SAMPLE 1: THE INITIAL RESULT WAS 7.6%. THE REPEAT RESULT AT ANOTHER SITE WAS 6.6%. SAMPLE 2: THE INITIAL RESULT WAS 5.9%. THE REPEAT RESULT AT ANOTHER SITE WAS 5.1% THE TEST WAS REPEATED AFTER MEDICAL PERSONNEL QUESTIONED THE RECOVERY IN SEVERAL PATIENT SAMPLES. THE REPEAT RESULTS WERE DEEMED CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25257823 ↗
• MalfunctionMay 22, 2026Non Reproducible Results

  WE RECEIVED AN ALLEGATION ABOUT DISCREPANT RESULTS FOR 2 PATIENTS' SAMPLES TESTED WITH CALCIUM GEN.2 ASSAY, 2 PATIENTS' SAMPLES TESTED WITH GLUCOSE HK GEN.3 ASSAY, 1 PATIENT SAMPLE TESTED WITH ALKALINE PHOSPHATASE ACC. TO IFCC GEN.2 ASSAY, ALANINE AMINOTRANSFERASE ACC. TO IFCC II ASSAY, CALCIUM GEN.2 ASSAY, TOTAL PROTEIN GEN.2 ASSAY, 1 PATIENT SAMPLE TESTED WITH MAGNESIUM GEN.2 ASSAY, 1 PATIENT SAMPLE TESTED WITH TOTAL PROTEIN ASSAY, 1 PATIENT SAMPLE TESTED WITH HDL-CHOLESTEROL GEN.4 ASSAY ON A COBAS C 303 ANALYTICAL UNIT. PATIENT 1: CALCIUM: INITIAL RESULT: 6.5 MG/DL. REPEAT RESULT: 10.0 MG/DL. PATIENT 2: GLUCOSE: INITIAL RESULT: 14.8 MG/DL. REPEAT RESULT: 96.3 MG/DL, AND THIS RESULT WAS DEEMED TO BE CORRECT. PATIENT 3: ALKALINE PHOSPHATASE: INITIAL RESULT: 56.7 U/L. REPEAT RESULT: 127 U/L. ALANINE AMINOTRANSFERASE: INITIAL RESULT: 16.7 U/L. REPEAT RESULT: 32.9 U/L. CALCIUM: INITIAL RESULT: 1.84 MG/DL (ACCOMPANIED BY A DATA FLAG). REPEAT RESULT: 9.07 MG/DL. TOTAL PROTEIN: INITIAL RESULT: 3.14 G/DL. REPEAT RESULT: 5.84 G/DL. PATIENT 4: MAGNESIUM: INITIAL RESULT: 3.95 MG/DL (ACCOMPANIED BY A DATA FLAG). REPEAT RESULT: 2.15 MG/DL. PATIENT 5: TOTAL PROTEIN: INITIAL RESULT: 7.60 G/DL.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25257321 ↗
• MalfunctionMay 19, 2026High Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE SODIUM RESULTS FOR QC AND PATIENT SAMPLES FROM THE COBAS C 303 ANALYTICAL UNIT. EXAMPLE 1 WAS AN INITIAL RESULT OF 154 MMOL/L, AND A REPEAT RESULT WAS 148 MMOL/L. EXAMPLE 2 WAS AN INITIAL RESULT OF 149 MMOL/L, AND A REPEAT RESULT WAS 142 MMOL/L. THE REPEAT RESULTS WERE BELIEVED TO BE CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25220905 ↗
• MalfunctionMay 8, 2026High Test Results

  WE RECEIVED AN ALLEGATION ABOUT DISCREPANT RESULTS FOR 1 PATIENT SAMPLE TESTED WITH BICARBONATE LIQUID ASSAY ON A COBAS C 303 ANALYTICAL UNIT. INITIAL RESULT: 36 MMOL/L. THE INITIAL RESULT DID NOT MATCH TEH PATIENT'S CLINICAL PICTURE, PROMPTING THE REPEAT OF THE SAMPLE. NO QUESTIONABLE RESULT WAS REPORTED OUTSIDE THE LABORATORY. REPEAT RESULT: 24 MMOL/L. THE REPEAT RESULT WAS DEEMED TO BE CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25126559 ↗
• MalfunctionMay 6, 2026High Test Results

  THE INITIAL REPORTER RECEIVED QUESTIONABLE SODIUM ELECTRODE AND ISE INDIRECT NA-K-CL FOR GEN.2 ASSAY RESULTS FROM 13 PATIENT SAMPLES TESTED ON THE COBAS C 303 ANALYTICAL UNIT. THE FOLLOWING ARE THE PATIENT SAMPLES IDENTIFIED TO HAVE DISCREPANT RESULTS FROM THE LIST PROVIDED: ON (B)(6) 2026: PATIENT SAMPLE 1 THE INITIAL SODIUM RESULT FROM THE ANALYZER WAS 148.4 MMOL/L. THE REPEAT RESULT FROM ANOTHER COBAS ANALYZER WAS 139.9 MMOL/L. PATIENT SAMPLE 2 THE INITIAL SODIUM RESULT FROM THE ANALYZER WAS 146.2 MMOL/L. THE REPEAT RESULT FROM ANOTHER COBAS ANALYZER WAS 138.2 MMOL/L. ON (B)(6) 2026: PATIENT SAMPLE 3 THE INITIAL CHLORIDE RESULT FROM THE ANALYZER WAS 102.2 MMOL/L. THE REPEAT RESULT FROM ANOTHER COBAS ANALYZER WAS 90.7 MMOL/L. THE INITIAL RESULTS WERE DEEMED HIGH AND WERE QUESTIONED BY THE DOCTORS, PROMPTING THE RERUN. THE REPEAT RESULTS WERE DEEMED CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25092576 ↗
• MalfunctionApr 17, 2026High Test Results

  THE INITIAL REPORTER RECEIVED QUESTIONABLE SODIUM ELECTRODE AND ISE INDIRECT NA-K-CL FOR GEN.2 ASSAY RESULTS FOR FOUR PATIENT SAMPLES TESTED ON THE COBAS C 303 ANALYTICAL UNIT. THE FOLLOWING ARE EXAMPLES OF PATIENT SAMPLES IDENTIFIED TO HAVE DISCREPANT RESULTS FROM THE LIST PROVIDED: PATIENT SAMPLE 1 SODIUM THE INITIAL RESULT OF THE INITIAL PATIENT SAMPLE WAS 156.1 MMOL/L. THE PROVIDER QUESTIONED THE INITIAL RESULT. THE INITIAL RESULT OF A RECOLLECTED PATIENT SAMPLE WAS 140.1 MMOL/L. THE REPEAT RESULT OF THE INITIAL PATIENT SAMPLE WAS 141.3 MMOL/L. THE REPEAT RESULT OF THE RECOLLECTED PATIENT SAMPLE WAS 141.3 MMOL/L. PATIENT SAMPLE 2 SODIUM THE INITIAL RESULT FROM THE ANALYZER WAS 165.6 MMOL/L. THE REPEAT RESULT FROM ANOTHER C 303 ANALYZER WAS 140.1 MMOL/L. CHLORIDE THE INITIAL RESULT FROM THE ANALYZER WAS 121.3 MMOL/L. THE REPEAT RESULT FROM ANOTHER C 303 ANALYZER WAS 106.4 MMOL/L. THE REPEAT RESULTS WERE DEEMED CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24910898 ↗
• MalfunctionApr 13, 2026Non Reproducible Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE SODIUM ELECTRODE RESULTS FOR 1 PATIENT SAMPLE ON A COBAS C 303 ANALYTICAL UNIT. THE INITIAL RESULT WAS 134.2 MMOL/L. THE REPEATED RESULT WAS 139.8 MMOL/L. NEITHER RESULT WAS BELIEVED TO BE CORRECT. THE SAMPLE WAS REPEATED BECAUSE THE CUSTOMER NOTICED THE NEGATIVE ANON GAP IN THE MIDDLEWARE SYSTEM.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24862903 ↗
• MalfunctionApr 3, 2026Incorrect Measurement; Non Reproducible Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE SODIUM ELECTRODE RESULTS FOR 1 PATIENT SAMPLE ON A COBAS C 303 ANALYTICAL UNIT. THE INITIAL NA RESULT WAS 163.2 MMOL/L, AND THE REPEATED RESULT WAS 151.7 MMOL/L. THE SAMPLE WAS REPEATED BECAUSE THE RESULT WAS MARKED AS CRITICAL IN THE CUSTOMER'S SYSTEM.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24779718 ↗
• MalfunctionMar 23, 2026Low Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE SODIUM ELECTRODE RESULTS FOR 2 PATIENT SAMPLES ON A COBAS C 303 ANALYTICAL UNIT. SAMPLE 1: THE INITIAL RESULT WAS 134 MMOL/L, AND THE REPEATED RESULT WAS 141.3 MMOL/L. SAMPLE 2: THE INITIAL RESULT WAS 132 MMOL/L, AND THE REPEATED RESULT WAS 139 MMOL/L. THE SAMPLES WERE REPEATED BECAUSE THE PHYSICIAN QUESTIONED THE INITIAL RESULTS. THE REPEATED RESULTS WERE BELIEVED TO BE CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24668959 ↗
• MalfunctionMar 23, 2026Low Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE SODIUM ELECTRODE RESULTS FOR 2 PATIENT SAMPLES ON A COBAS C 303 ANALYTICAL UNIT. SAMPLE 1: THE INITIAL RESULT WAS 131.9 MMOL/L, AND THE REPEATED RESULT WAS 139.9 MMOL/L. SAMPLE 2: THE INITIAL RESULT WAS 131.6 MMOL/L, AND THE REPEATED RESULT WAS 137.6 MMOL/L. THE REPEATED RESULTS WERE OBTAINED ON ANOTHER MODULE AND WERE BELIEVED TO BE CORRECT. THE SAMPLES WERE REPEATED BECAUSE THE INITIAL RESULTS WERE QUESTIONED BY THE PHYSICIAN.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24668038 ↗
• MalfunctionMar 17, 2026Non Reproducible Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE POTASSIUM ELECTRODE RESULTS FOR 1 PATIENT SAMPLE ON A COBAS C 303 ANALYTICAL UNIT. THE INITIAL RESULT WAS 7.03 MMOL/L. THE CUSTOMER QUESTIONED THE RESULT, WHICH PROMPTED THEM TO REPEAT THE SAMPLE. THE REPEAT RESULT WAS 3.87 MMOL/L. NO QUESTIONABLE RESULTS WERE REPORTED OUTSIDE OF THE LABORATORY.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24620140 ↗
• MalfunctionMar 17, 2026High Test Results

  THE INITIAL REPORTER STATED THEY RECEIVED DISCREPANT RESULTS FOR TWO PATIENT SAMPLES TESTED WITH THE POTASSIUM ELECTRODE ON A COBAS C 303 ANALYTICAL UNIT. THE FIRST SAMPLE INITIALLY RESULTED IN A POTASSIUM VALUE OF 6.2 MMOL/L. THE VALUE WAS DEEMED CRITICAL AND DID NOT AGREE WITH THE PATIENT'S CLINICAL STATUS, SO THE SAMPLE WAS REPEATED. THE REPEAT RESULT WAS 3.8 MMOL/L AND THIS VALUE WAS DEEMED CORRECT. THE SAMPLE WAS REPEATED FIVE ADDITIONAL TIMES, EACH TIME RESULTING IN A VALUE OF 3.8 MMOL/L. ON AN UNKNOWN DATE IN THE FALL OF 2025, A SECOND PATIENT SAMPLE INITIALLY RESULTED IN A POTASSIUM VALUE OF 9.0 MMOL/L AND IT REPEATED AS 4.2 MMOL/L. NO QUESTIONABLE RESULTS WERE REPORTED OUTSIDE OF THE LABORATORY FOR THIS SAMPLE.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24616178 ↗
• MalfunctionMar 12, 2026Low Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE ISE INDIRECT NA-K-CL FOR GEN.2 (CL) RESULTS FOR 1 PATIENT SAMPLE ON A COBAS C 303 ANALYTICAL UNIT. THE INITIAL CL RESULT WAS 79.2 MMOL/L. THE CUSTOMER'S LABORATORY INFORMATION SYSTEM FLAGGED THE RESULT WITH A DELTA CHECK WHICH PROMPTED THE CUSTOMER TO REPEAT THE SAMPLE. THE REPEAT RESULT WAS 99.8 MMOL/L.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24584413 ↗
• MalfunctionMar 12, 2026High Test Results

  WE RECEIVED AN ALLEGATION ABOUT DISCREPANT RESULTS FOR 1 PATIENT SAMPLE TESTED WITH BIL-D GEN.2 ASSAY ON COBAS C 303 ANALYTICAL UNIT. THE ORIGINAL SAMPLE WAS USED TO RUN 2 DIFFERENT ACCESSION NUMBERS (SAMPLE 1 AND SAMPLE 2). SAMPLE 1: INITIAL RESULT: 0.379 MG/DL (ACCOMPANIED BY A DATA FLAG). 1ST REPEAT RESULT: 2.79 MG/DL (ACCOMPANIED BY A DATA FLAG). 2ND REPEAT RESULT: 5.30 MG/DL (ACCOMPANIED BY A DATA FLAG). SAMPLE 2: INITIAL RESULT: 0.374 MG/DL (ACCOMPANIED BY A DATA FLAG). 1ST REPEAT RESULT: 5.8 MG/DL (ACCOMPANIED BY A DATA FLAG). 2ND REPEAT RESULT: 5.52 MG/DL (ACCOMPANIED BY A DATA FLAG). THE INITIAL RESULTS WERE GENERATED USING A DILUTION FACTOR OF 1:50 ORDERED BY THE CUSTOMER. THE PHYSICIAN QUESTIONED THE INITIAL RESULTS AS THEY DID NOT MATCH THE PATIENT'S CLINICAL STATUS, PROMPTING THE REPEAT OF SAMPLE 1 AND SAMPLE 2. REPORTEDLY, THE REPEAT RESULTS OF 5.30 MG/DL AND 5.52 MG/DL WERE REPORTED OUTSIDE THE LABORATORY.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24579312 ↗
• MalfunctionMar 6, 2026High Test Results

  WE RECEIVED AN ALLEGATION OF QUESTIONABLE SODIUM ELECTRODE ASSAY RESULTS FOR MULTIPLE PATIENT SAMPLES TESTED ON THE COBAS C 303 ANALYTICAL UNIT. ONE PATIENT SAMPLE WITH DISCREPANT RESULTS WAS PROVIDED: THE INITIAL RESULT FROM THE ANALYZER IS 142 MMOL/L. THE REPEAT RESULT FROM A COBAS PRO ISE IS 128 MMOL/L. THE REPEAT RESULT WAS DEEMED CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24536476 ↗
• MalfunctionMar 6, 2026High Test Results; Non Reproducible Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE POTASSIUM ELECTRODE RESULTS FOR 1 PATIENT SAMPLE ON A COBAS C 303 ANALYTICAL UNIT. THE INITIAL RESULT WAS APPROXIMATELY 7.0 MMOL/L. THE REPEATED RESULT WAS APPROXIMATELY 3.5 MMOL/L. THE REPEATED RESULT WAS BELIEVED TO BE CORRECT. THE SAMPLE WAS REPEATED BECAUSE THE INITIAL RESULT WAS MARKED AS CRITICAL.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24529684 ↗
• MalfunctionMar 6, 2026High Test Results; Non Reproducible Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE POTASSIUM ELECTRODE RESULTS FOR 1 PATIENT SAMPLE ON A COBAS E 402 ANALYTICAL UNIT. THE INITIAL RESULT WAS 6.0 MMOL/L. THE RESULT WAS MARKED AS CRITICAL, AND A NEW SAMPLE WAS OBTAINED. THE RESULT FROM THE NEW SAMPLE WAS 3.7 MMOL/L. DUE TO THE DISCREPANCY IN RESULTS, THE INITIAL SAMPLE WAS RESPUN AND RETESTED, AND THE RESULT WAS 3.9 MMOL/L. THIS RESULT WAS BELIEVED TO BE CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24529350 ↗
• MalfunctionFeb 27, 2026High Test Results; Non Reproducible Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE POTASSIUM RESULTS FROM THE COBAS C 303 ANALYTICAL UNIT. THE INITIAL RESULT WAS 5.7 MMOL/L. THE REPEAT RESULT WAS 3.8 MMOL/L. A NEW SAMPLE WAS DRAWN FROM THE PATIENT, AND THE RESULT WAS 3.8 MMOL/L. THE RESULT OF 3.8 MMOL/L WAS BELIEVED TO BE CORRECT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24470377 ↗
• MalfunctionFeb 25, 2026High Test Results; Non Reproducible Results

  THE INITIAL REPORTER COMPLAINED OF A DISCREPANT HIGH RESULT FOR 1 PATIENT SAMPLE TESTED FOR TINA-QUANT HEMOGLOBIN A1CDX GEN.3 (A1CX3) ON A COBAS C 303 ANALYTICAL UNIT. THE INITIAL RESULT WAS 17.5% WITH A DATA FLAG. THE DOCTOR QUESTIONED THIS RESULT. THE SAMPLE WAS REPEATED TWICE, WITH RESULTS OF 4.99% AND 4.93%.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24441846 ↗