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Immunoenzymatic/immunohistochemical (IHC) staining techniques allow for the qualitative identification of tissue antigens. Antigens are visualized via the sequential application of a specific antibody to the antigen (primary antibody) and a detection system. Immunohistochemical detection systems usually consist of a secondary antibody to the primary antibody (link antibody), an enzyme complex and a chromogenic substrate. The enzymatic activation of the chromogen yields a visible reaction product at the antigen site. Results aid in the diagnosis of pathophysiological processes which may or may not be associated with a particular antigen.

The DAKO LSAB® 2 Kit, HRP (Code No. K0677) is based on a modified labeled avidin-biotin (LAB) technique in which a biotinylated secondary antibody forms a complex with peroxidase-conjugated streptavidin molecules. This kit is very similar to the original DAKO LSAB® Kit, HRP (K0680) previously cleared in submission K924726. Refinements to the LSAB® 2 Kit include the elimination of a separate protein blocking reagent incubation and reconfigured substrate-chromogen reagents.

The DAKO Envision™ Systems, HRP, contains a Peroxidase Blocking Reagent similar to the Hydrogen Peroxide provided with the LSAB® and LSAB® 2 Kit, the Envision™ System does not require a protein blocking reagent incubation. The Envision™ System also eliminates the sequential applications of link antibody and streptavidin common to the LSAB® 2 Kits. A polymer, labeled with goat anti-mouse and goat anti-rabbit immunoglobulins conjugated to horseradish peroxidase eliminates these steps. The DAKO Envision™ System offers the user a choice of two protocols. Protocol #1 consecutively incubates the primary antibody and Peroxidase Labeled Polymer for ten (10) minutes. Protocol #2 increases the staining intensity of the Envision™ System by lengthening the incubations of the primary antibody and the labeled polymer to thirty (30) minutes. The DAKO Envision™ System. HRP, is available with DAB (Code No. K1390) or Ready-to-Use AEC substrate-chromogen (Code No. K1391). Both systems use the same Peroxidase Blocking Reagent and Peroxidase Labeled Polymer.

Concentrated primary rabbit/mouse antibodies or DAKO® Ready-to-Use N-Series Primary Antibodies and Negative Control Reagents are suitable for use with the DAKO LSAB® 2 Kit and DAKQ Envision™ Systems. Primary antibodies are not included with the DAKO LSAB® 2 Kit, HRP or DAKO Envision™ Systems, and must be purchased separately by the user.

The provided text describes the DAKO LSAB® 2 Kit, HRP, and DAKO Envision™ Systems, HRP, which are immunohistochemical (IHC) staining systems used for qualitative identification of tissue antigens. The document is a Summary of Safety and Effectiveness for a K951965 submission.

Here's an analysis of the provided information against the requested categories:

1. A table of acceptance criteria and the reported device performance

2. Sample sizes used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

• Sample Size: The document repeatedly mentions "all test specimens" and specific tissue types like "tonsil" and "melanoma", and "liver," "kidney," and "lymphoid tissues." However, no specific numerical sample sizes are provided for any of the comparative tests. The sample size for the comparison of LSAB2 with 2-component AEC versus ready-to-use AEC for specific antibodies (LCA, UCHL1, HMB45) is denoted by "N1514," "N1520," and "N1545" in parentheses next to the antibody names, implying these might refer to specific tissue samples or an internal numbering system, but the actual number of specimens is not listed.
• Data Provenance: The document does not specify the country of origin of the data. The data appears to be retrospective in nature, as it describes comparisons of the new devices against existing products using various tissue types.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)

• The document does not specify the number of experts used to establish the ground truth or interpret the results.
• It also does not provide any qualifications for the individuals who performed the interpretation/evaluation ("Equivalent interpretive results were observed," "Results showed that the same level of staining was obtained," "Background staining... evaluated as negative").

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

• The document does not describe any formal adjudication method for the test set. The evaluations appear to be direct comparisons of staining results.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

• No MRMC comparative effectiveness study was performed.
• This device is an IHC staining kit, not an AI or imaging diagnostic device. Therefore, the concept of "human readers improve with AI vs. without AI assistance" is not applicable here.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

• This question is not applicable as the device is an IHC staining kit and not an algorithm or AI system.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

• The ground truth appears to be based on visual interpretation of staining results by unspecified individuals, likely experienced researchers or pathologists within DAKO, evaluating "equivalent interpretive results," "level of staining," and "background staining." This is implicitly based on established immunohistochemical principles and the expected reactivity of the primary antibodies on the tested tissues.

8. The sample size for the training set

• The document describes comparative testing of new kits against existing kits and variations within the new kits. It does not mention a "training set" in the context of machine learning or algorithm development, as these are chemical kits. All described tests appear to be evaluations of the final products.

9. How the ground truth for the training set was established

• As there is no "training set" in the context of this device type, this question is not applicable. The "ground truth" for the performance evaluations (test sets) was established by visual assessment of staining consistency and intensity by presumably qualified personnel.

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