Puneet Varma (Editor)

Lysine iron agar slant

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit

The lysine iron agar slant or LIA slant test is used to distinguish bacteria which are able to decarboxylate lysine and/or produce hydrogen sulfide from those that cannot. This test is particularly useful for distinguishing different Gram-negative bacilli—especially among the Enterobacteriaceae.

Procedure

The LIA slant is inoculated by stabbing the agar to within 1/4 inch of the butt of the tube and streaking the slant. The slant is then incubated at 35°C for 18–24 hours. The results are scored as follows:

  • purple slant/yellow butt = LSI Negative
  • turbid, purple butt = LSI Positive
  • black precipitate = H2S Positive
  • References

    Lysine iron agar slant Wikipedia