Sample Accessioning/LIMS Requirements

All LIMS products have a sample accessioning capability, usually centered on a case number. Each case number has multiple items, or submissions, associated with it. Some LIMS may print a barcode that assists in chain-of-custody documentation and the creation of management or status reports.

In a mass fatality incident response, human remains, personal items, and kinship samples must be accessioned. Laboratories usually retrofit these special requirements into their existing LIMS. There are a number of benefits to this approach, including that:

• Laboratory personnel are familiar with the sample accessioning process and can avoid the learning curve associated with new software.
• Chain of custody is documented and controlled using tried-and-true processes already in place.
• There is no need to purchase additional software.

The typical strategy for accessioning human remains is to assign all fragment submissions to a single case number. This is relatively straightforward if the LIMS allows a single case to have thousands of submissions (one for each remains sample). If the laboratory’s LIMS does not allow for a large number of samples to be associated with a case, the laboratory will want to consider developing a system to link the cases so that all samples can be associated to each other and to the identification effort.

The commingling of remains presents another problem. For example, after a remains sample is accessioned and analyzed, the laboratory may discover that it belongs to two or more individuals. The DNA may show that the bone and tissue come from different donors, as happened in the WTC attacks, where remains were severely compacted.

From the moment commingling is discovered, the laboratory will have to assign a new submission number to one of the items, then track both items separately. This principle would apply even if there are more than two profiles from a single sample—each profile would require a new submission number. Some LIMS systems may allow a sample to have multiple DNA profiles; regardless, both samples will have to share the initial chain-of-custody and accessioning information.

Several other scenarios may further confound sample tracking. For example, there may be multiple victims from the same family, in which case the situation is complicated by partial profiles with overlapping genotypes or by full or nearly full DNA profiles from remains that are needed as reference samples for a related victim. Such difficult situations can occur and must be accommodated.

The typical strategy for accessioning reference samples is to assign each victim a case number and add reference samples as submissions under the case. The case number is important because it represents the victim’s family and is used to group personal items and kinship samples for kinship matching.

Assigning case numbers is not a complicated issue in a “closed” incident—for example, when a flight manifest contains names and addresses that can be tracked. During reference sample collection in a closed event, the family assistance center can review the list of victims and assign reference samples to the correct case number. In instances where victims have similar names, the family assistance center can ask family members for clarification during the collection process.

However, assigning case numbers in an “open” incident is much more complicated and may tax the capabilities of the laboratory’s LIMS. Because there is no definitive list of victims in an open incident situation, the family assistance center—not knowing, for example, if there is more than one victim named John Smith—cannot simply assign case numbers to victims. This problem is exacerbated when reference samples are collected in an open-house forum, where members of the same family visit the collection center at different times. This also can lead to errors in the collection process, including variations of a victim’s name and perhaps even date of birth.

Therefore, during accessioning, staff entering data should avoid the temptation to reconcile name variations. Rather, data should be entered exactly as specified on the collection form. Any necessary case number or victim reconciliation should occur after the final list of victims is established. This approach to accessioning will generate more case numbers than victims, but it will preserve all the information provided by the donors.

Unless care is taken when identifying and assigning case numbers to the potential victims, the laboratory will be forced to reconcile originally assigned case numbers with a later, more refined list of case numbers. Some of the originally assigned case numbers might have to be divided, and others might have to be consolidated. The most important part of a process that requires a regrouping of reference samples is preserving the original case number so that:

• Samples do not have to be barcoded again.
• New case numbers do not have to be issued to families.
• The chain of custody is maintained.

Exhibit 15 presents different scenarios of reconciling case numbers with victims. It is important to keep in mind that some LIMS products may not allow reconciliation of case numbers with victims. Exhibit 16 presents some additional capabilities that require LIMS support.

If possible, the software used by the family assistance center to collect reference samples should interface with the laboratory’s LIMS. This avoids duplicate data entry and eliminates the potential for data-entry errors. At a minimum, the two systems should have compatible barcodes so that the samples do not have to be barcoded again during accessioning.

Ideally, the laboratory’s LIMS will be able to:

• Store the data included in the reference sample collection forms:
• Sample Personal Items Submission Form
• Sample Family and/or Donor Reference Collection Form
• Sample Family Tree Form
• Capture photographs of remains samples and personal items and digital images of handwritten collection forms.
• Store family pedigrees and allow a victim sample to be used as a reference sample for another victim, if necessary.
• Allow cases to be divided and combined.
• Track samples to and from multiple laboratories.
• Track multiple testing of the same sample.
• Alert the end user to discrepancies in data.
• Prioritize sample testing and data analysis.

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