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5.3Gastric Lavage
1. Gastric Lavage should be processed immediately upon arrival in the lab to
prevent the killing action of the gastric pH (due to HCl) on the tubercle
bacilli
2.
3. Place one drop of the final pellet on the direct smear
4.
Inoculate two slopes each of
LJ and LJ-P with one loopful of deposit for each
slope
5. Transfer the remaining deposit in to one bottle of SK
6. Incubate the slopes and SK medium at
37
o
C
5.4Tissue / Biopsy
1. Ideally, biopsy specimens should be collected and transported in SK
medium
2. Carefully place the tissue inside a sterile petriplate inside the BSC
3.
Using sterile scissors and forceps, cut the tissue in to tiny pieces
4.
Transfer to a sterile tissue grinding tube add a little water to the
petriplate to facilitate transferring
5.
Add sterile distilled water to the tube (not more than 5 ml)
6. Homogenise using a sterile Teflon grinding rod using a foot operated
tissue grinder
7. Make a direct smear from the homogenate
8. Centrifuge the homogenate at 3000 x g for 15 minutes
9. Decant the supernatant carefully in to the disinfectant bath
10.Tothe deposit add 1 ml of sterile distilled water
11.Add one drop to the direct smear, air dry, fix and stain
12.Tothe remaining pellet, add 1ml of
5% H
2
SO
4
13.Proceed as for CSF
14. Inoculate two slopes each of LJ and LJ-P with one loopful of deposit for
each slope
15.Transfer the remaining deposit in to one bottle of SK
16. Incubate the slopes and SK medium at 37
o
C, along with the SK medium
used for transporting
5.5Fine Needle Biopsy specimen
1. Fine needle specimens should be collected and transported only in SK
medium or any other liquid medium
2. The medium is incubated as such at
37
o
C,
since only a very tiny piece of
the tissue is obtained as sample
If the sample is received without SK
1. Add the contents of two SK medium bottles to the specimen
2.
Shake vigorously and let stand for 10 minutes
3.
Divide the medium in to two aliquots and incubate both at 37
o
C
5.6 Pus
1. Make a direct smear, air dry, fix and stain
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