由特殊的阻擋膜組成，能防止與酶有關的顏色反應而污染其他樣品，并阻止與皮膚的直接接觸。

袋子表面有4 oz. and 100 ml的容積標志線和顏色比較條帶。

直立型袋子，已預先滅菌，請放心使用。
100 ml, Coli-Test® 大腸菌群取樣袋（用于Colilert® 和Colitag® 試劑）

If water samples are being tested with color-changing reagents, this bag can be used in place of the expensive bottle currently used. The bag is made of a special barrier film suitable for use with enzyme-based methods that result in a chromogen and/or a fluorogen release when total coliform and E. coli are present. The special film prevents color change from permeating through the bag, contaminating another sample and creating a false positive, and making contact with a person’s skin if they are not wearing gloves. It is sterile, contains 10 mg of active sodium thiosulfate to neutralize chlorine, has 4 oz. and 100 ml fill lines, and is compley self-standing – no rack or holder is needed to keep the bag upright. If the sample is not chlorinated, this bag can still be used; the sodium thiosulfate will not affect the sample, it is nontoxic and nonnutritive, and only neutralizes chlorine if present. A free color comparator is included in every box.

The Coli-Test bag has been accepted by the EPA and is listed in the EPA Manual for the Certification of Laboratories Analyzing Drinking Water Section 5.3.1.4, 5th edition, January 2005.

The Coli-Test bag will save money three ways: less expensive than the bottle, lower freight charges, and reduced disposal costs. A box containing 100 bags measures 9" x 7" x 2" （23 x 18 x 5 cm）, weighs 1 lb. （0.40 kg）, compared to a box of bottles which has considerable more volume and weight.