In 2 additional approaches, we pooled the iWGA products of 5 single cells and the products of 3 single cells (Table 2; see Table 3 in the online Data Supplement) after DNA fingerprint
analysis revealed the cells to be of HT-29 origin.
At this point, I show students a poster-board representation of the DNA fingerprint
gel from the crime scene (Figure 1) and ask them to use the data and decide who committed the crime.
In November 1998, NTGSN detected 11 isolates from previously reported TB cases among persons in New Jersey whose DNA fingerprints
matched the avirulent laboratory M.
Early in the outbreak, BCHD recognized the initial cluster of four cases with matching DNA fingerprint
An index of similarity (|S.sub.xy~; e.g., Lynch 1990, 1991) between DNA fingerprints
was calculated as the number of bands shared between each pair of individuals (|n.sub.xy~) divided by the total number of bands scored for both individuals (|n.sub.x~ + |n.sub.y~),
Studies are increasingly using levels of clustering of isolates from tuberculosis cases (proportion sharing identical DNA fingerprint
patterns) to estimate the extent of disease attributable to recent transmission.
clustering of isolates among groups at high risk could represent a relatively more specific marker of recent transmission when compared to clustering identified in the general population.
Transmission was considered confirmed if matching DNA fingerprint
patterns were found in both isolates from a case pair.
A study conducted in Arkansas suggests that DNA fingerprint
clustering in stable rural populations may result from remote rather than recent transmission (6).
tuberculosis transmission among patients whose isolates have similar but not identical DNA fingerprint
patterns (i.e., differing by a single band) has not been well documented.
In addition, the panel recommends the formation of a National Committee on Forensic DNA Typing to keep up with innovations in DNA fingerprinting methods, and the creation of a nationwide DNA fingerprint
database if current pilot studies prove its usefulness in tracking criminals.
In a previous study, homelessness was the key factor associated with DNA fingerprint
clustering, suggesting that ongoing transmission of TB in Denver, Colorado, occurs primarily among the homeless (4).