Sending stool specimens to a distant laboratory for bacteriologic identification has always been unsatisfactory. The dried filter paper technique has proved to be an efficient, simple and cheap solution of the problem.
On a clean piece of filter paper 6 to 10 drops of stool are placed and dried at room temperature. For dysenteric stools the mucous parts are selected. A firm stool should be mixed with water to make it semiliquid before dropping it on the filter paper. To obtain satisfactory results the following procedure should be performed:
1.The stool should be dried as soon as possible after defecation.
2.It is essential to dry thick fecal drops; thin drops are unsatisfactory. To reduce the drying period to not more than three hours thick drops should be made having a diameter of about 0.5 cm. consisting of about 0.2 cc. of mucus or stool. The drops should be separated about 5 cm. from each other to allow the moisture to be absorbed by the surrounding paper.