E. coli NA22 strain information

Good Day to all.

Here im curious on how to have a test to confirm the strain of e. coli that we used to feed the worm since the contamination could occur during the lab work. Is there any method I can use to confirm that the strain was E. coli NA22 and there is no contamination. Perhaps the morphology, or any other test to confirm it. I really appreaciate your sharing cause I feel that my NA22 was contaminated. The morphology kind of a little bit strange. Is there any selective medium for NA22? And is there any way to cryo the NA22? Thank you in advance.

I haven’t looked for the genotype of NA22, nor do I know whether it is resistant to any antibiotics (I’d doubt it), but you can request a new copy of NA22 from the CGC, and you can make a frozen stock with standard methods (in a labeled cryotube, mix a stationary-phase culture with autoclaved 50% glycerol to a final concentration of 15-30% glycerol and place in the -80 freezer; the desired concentration depends on the desired consistency). You can then grow your bacterial broths from streaked-out single colonies; whenever you have doubts, start a new culture growing from your frozen stock

If there is no other way, I also plan to request again NA22 from CGC. Because I didnt expect this will happen since Im new to this and method to frozen it was unclear. Thank for your guide. Thank you alot Hillel.