← Product Code [MHJ](/submissions/MI/subpart-d%E2%80%94serological-reagents/MHJ) · K052932

# CRYPTOSPORIDIUM II (K052932)

_Techlab, Inc. · MHJ · Nov 4, 2005 · Microbiology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/MHJ/K052932

## Device Facts

- **Applicant:** Techlab, Inc.
- **Product Code:** [MHJ](/submissions/MI/subpart-d%E2%80%94serological-reagents/MHJ.md)
- **Decision Date:** Nov 4, 2005
- **Decision:** SESE
- **Submission Type:** Special
- **Regulation:** 21 CFR 866.3220
- **Device Class:** Class 2
- **Review Panel:** Microbiology

## Indications for Use

The CRYPTOSPORIDIUM II test is an enzyme immunoassay for the qualitative detection of Cryptosporidium oocyst antigen in human fecal specimens. It is indicated for use as an aid in the diagnosis of patients with diarrhea suspected of Cryptosporidium gastrointestinal infection. FOR IN VITRO DIAGNOSTIC USE.

## Device Story

Cryptosporidium II is an enzyme-linked immunosorbent assay (ELISA) for detecting Cryptosporidium oocysts in fecal samples. It utilizes a direct conjugate format where the detecting antibody is labeled with horseradish peroxidase (HRP), simplifying the procedure by reducing incubation and washing steps compared to the indirect format of the predicate. The device uses a one-component substrate containing tetramethylbenzidine and peroxide, which provides higher color intensity. It includes a sample diluent compatible with both fresh and sodium acetate formalin (SAF) preserved fecal samples. The test is performed by laboratory personnel. Results are determined by color reactivity, which indicates the presence of oocysts. The modification to a direct conjugate and one-component substrate enhances usability and safety (less caustic stop solution) without altering the fundamental scientific technology or clinical performance.

## Clinical Evidence

No clinical data provided in the document.

## Technological Characteristics

Enzyme immunoassay (EIA) for antigen detection. In vitro diagnostic device.

## Regulatory Identification

Entamoeba histolytica serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to Entamoeba histolytica in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identify Entamoeba histolytica directly from clinical specimens. The identification aids in the diagnosis of amebiasis caused by the microscopic protozoan parasite Entamoeba histolytica and provides epidemiological information on diseases caused by this parasite. The parasite may invade the skin, liver, intestines, lungs, and diaphragm, causing disease conditions such as indolent ulcers, an amebic hepatitis, amebic dysentery, and pulmonary lesions.

## Special Controls

*Classification.* Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.

## Submission Summary (Full Text)

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SPECIAL 510(k): Device Modification

ODE Review Memorandum (Decision Making Document is Attached)

To: THE FILE

RE: DOCUMENT NUMBER k052932

This 510(k) submission contains information/data on modifications made to the SUBMITTER'S own Class II, Class III or Class I devices requiring 510(k). The following items are present and acceptable (delete/add items as necessary):

1. The name and 510(k) number of the SUBMITTER'S previously cleared device. (For a preamendments device, a statement to this effect has been provided.)
2. Submitter's statement that the INDICATION/INTENDED USE of the modified device as described in its labeling HAS NOT CHANGED along with the proposed labeling which includes instructions for use, package labeling, and, if available, advertisements or promotional materials (labeling changes are permitted as long as they do not affect the intended use).
3. A description of the device MODIFICATION(S), including clearly labeled diagrams, engineering drawings, photographs, user's and/or service manuals in sufficient detail to demonstrate that the FUNDAMENTAL SCIENTIFIC TECHNOLOGY of the modified device has not changed.

The changes identified were as follows:

1. A direct conjugate format will replace an indirect conjugate format making the test simpler to perform. The detecting antibody is directly labeled with horseradish peroxide IgG:HRP conjugate which would reduce the number of incubation and washing steps in the test procedure.
2. To replace a two-component substrate with a one-component substrate, making the test simpler to perform. Both the one and two component substrates use tetramethylbenzidine and peroxide. The one-component substrate has the same reactive components but was determined to give higher color intensity than the original two-component substrate. The end result is an enhancement of the color reactivity that slightly increases OD readings, but does not alter performance characteristics.
3. The stop solution was weakened from 1M sulfuric acid to 0.6N (equiv. to 3M) sulfuric acid rendering the reagent to be less caustic.
4. The addition of a sample diluent to accommodate both fresh and preserved fecal samples. The diluent makes the test compatible with samples preserved in sodium acetate formalin (SAF), a preservative not previously claimed for use with the predicate test.

|  Reagent | Cryptosporidium Test (Old device) | Cryptosporidium II (Modified device)  |
| --- | --- | --- |
|  Format | Indirect conjugate format | Direct conjugate format  |
|  Diluent | 1X Wash buffer | Buffered protein solution  |
|  Substrate | One drop of substrate A (tetramethylbenzidine substrate) followed by one drop of Substrate B (peroxide) | Two drops of one component Substrate containing tetramethylbenzidine substrate and peroxide  |
|  Stop solution | 1M sulfuric acid | 0.6N sulfuric acid  |
|  Negative control | 1X wash buffer | diluent  |
|  Dilutions | None for preserved, 1:5 for fresh | 1:3 for preserved, 1:15 for fresh  |
|  Detecting antibody | Rabbit anti-Cryptosporidium oocyst (Affinity purified rabbit antibody) | N/A-unconjugated detecting antibody is not utilized in this test  |
|  Conjugate | Goat-anti rabbit IgG:HRP | Rabbit anti-Cryptosporidium oocyst:HRP (Affinity purified rabbit antibody conjugated to horseradish  |

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|   |  | peroxidase)  |
| --- | --- | --- |

4. Comparison Information (similarities and differences) to applicant's legally marketed predicate device including, labeling, intended use, physical characteristics, and performance characteristics which included a comparison of this device test results to the legally marketed predicate device using 68 positive and 282 negative specimens in one study and 44 positive and 141 negative specimens in another study; freeze-thaw, inter- and intra- assay precision studies, cross reactivity studies, validation testing, and multi-site proficiency testing.

5. A Design Control Activities Summary which includes:

a) Identification of Risk Analysis method(s) used to assess the impact of the modification on the device and its components, and the results of the analysis.
b) Based on the Risk Analysis, an identification of the verification and/or validation activities required, including methods or tests used and acceptance criteria to be applied.

|  Risk analysis of Modification(s) | Impact/risk | Validation methods  |
| --- | --- | --- |
|  Indirect to Indirect format | Low-no change in antibody, studies demonstrated no change in performance | sensitivity, specificity, reproducibility studies (inter and intra assay precision), and cross reactivity study  |
|  Addition of a sample diluent | Low-studies demonstrated no change in performance and allows for use of SAF preserved specimens not previously claimed for use with the predicate test. | sensitivity, freeze thaw, and reproducibility studies  |
|  Change from two-component to one-component Substrate | Low-studies demonstrated no change in performance. One component was determined to give a higher color intensity than original two component substrate | sensitivity, specificity, reproducibility, and cross reactivity studies  |
|  Stop solution 1M to 0.6N sulfuric acid | Low-studies demonstrated no change in performance, reagent less caustic to the user | sensitivity and reproducibility studies  |
|  Dilutions-larger dilution of fecal samples is required in the new test device | Low-studies demonstrated no change in performance | sensitivity and reproducibility studies  |
|  Detecting antibody | Low- no change in antibody, studies demonstrated no change in performance | sensitivity, reproducibility, and cross reactivity studies  |
|  Conjugate | Low- studies demonstrated no change in performance | sensitivity, reproducibility, and cross reactivity studies  |

c) A declaration of conformity with design controls. The declaration of conformity should include:

i) A statement signed by the individual responsible, that, as required by the risk analysis, all verification and validation activities were performed by the designated individual(s) and the results demonstrated that the predetermined acceptance criteria were met, and
ii) A statement signed by the individual responsible, that the manufacturing facility is in conformance with design control procedure requirements as specified in 21 CFR 820.30 and the records are available for review.

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6. A Truthful and Accurate Statement, a 510(k) Summary or Statement and the Indications for Use Enclosure (and Class III Summary for Class III devices).

The labeling for this modified subject device has been reviewed to verify that the indication/intended use for the device is unaffected by the modification. In addition, the submitter's description of the particular modification(s) and the comparative information between the modified and unmodified devices demonstrate that the fundamental scientific technology has not changed. The submitter has provided the design control information as specified in The New 510(k) Paradigm and on this basis, I recommend the device be determined substantially equivalent to the previously cleared (or their preamendment) device.

Comments: Recommend SE determination

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**Source:** [https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/MHJ/K052932](https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/MHJ/K052932)

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