生化英语：此处的loop如何理解?
4.2 Enumeration by the MPN technique
4.2.2 Enrichment in selective liquid medium
Tubes of liquid enrichment broth (EE broth) are inoculated with each tube of culture obtained after pre-enrichment (at least 3 × 3).The tubes are inculated at 37℃ (30℃) for 24 h ± 2 h.
4.2.3 Isolation and selection for confirmation
A selective solid mediu,(violet red bile glucose agar) is inoculated with a loop from each of the incubated cultured botained after enrichment in EE broth,then incubated at 37℃ (30℃) .It is examined after 24 h ± 2 h to check for the presence of colonies presumed by their characteristics to be Enterrobacteriaceae.