Pathan A J, Arain A R.
Comparative study of Cold Stain and Ziehl-Neelsen Stain.
Pak J Chest Med Jan ;8(1):37-8.

Methods: Duplicate smears were prepared from 652 sputum specimens, one for Ziehl-neelsen staining and other for Cold Staining. Both were air dried. No heat fixation was performed for the latter. Ziehl-Neelsen staining was performed following the technical guide of IUAT (1978). The slides for Cold staining were placed on a slide-rack and were Covered by staining solution 9basic fuChin 1 G, 95% alcohol 10 ml, phenol 3 G, distilled water 100 ml) which was left for 25 minutes before being poured off. The slide was then Covered by decolourising Cum Counterstain solution (10% NaCl in water solution 10 ml, Methanol 90 ml + Methylene blue 100 mg) for 30 seconds, and then washed in gentle stream of water. The second step was repeated once again until the Colour of the smear became pale. Blue. The slide dried in air. The slides for both the staining method were examined independently under the microscope and the results using scores 0, doubtful (6) , +, ++, +++ were recorded. Results and Observations. The 652 pairs of slides were examined in parallel and Table was Compiled from the results. Identical results are shown on the diagonal. Scores higher by Ziehl-Neelsen technique are shown above the diagonal, and those higher by the Cold technique below it. Although scores were definitely higher by the Ziehl-Neelsen technique, the total yield of positive results from 652 specimens was only slightly higher by this technique, i.e. 607 scores, 628 (583 positive and 45 negative or doubtful) of the 652 pairs of smears gave identical results i.e. there w 96% agreement of 45 disagreement. It may be seen from table I that when Cold technique gave the result 0 or (6) , in only 24 of 69 instances (35%) did the Ziehl-Neelsen technique yield a positive result 9+, ++, or +++); in other words, there was agreement between the two techniques on negative results in 45 probability of agreement with the Ziehl-Neelsen technique was Complete i.e. 100%. The greatest extent of disagreement occurred when the results of the Cold technique reported were doubtful ( 6). The result of the Ziehl-Neelsen technique disagreed in 33 of 35 instances, being positive (6) in 17 Cases and negative in 16.

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