CF4 is a medium weight, 100% cotton linter material (482 µm thickness at 53 kPA), suitable for use as a sample and absorption pad for lateral flow and flow-through assays.

•     Medium weight.
•     Consistent absorbency and wicking rates: Ensures test-to-test reproducibility.
•     Product manufactured in controlled environments from high-quality materials: Minimizes the risk of false results due to sample contamination.
•     Low protein binding: High test sensitivity and minimal loss of analyte.
•     Naturally hydrophilic: Rapid rewetting after prolonged storage.
•     Compatible with most housing styles.

CF4 – Medium Grade Sample Pads

To ensure that your assay begins without complications, Cytiva offers a complete range of high-quality sample pad materials. CF4 is medium grade, suitable for use as a sample pad in lateral flow applications. Sample pads begin the assay by transporting samples from the point of application to the test components. CF4 can also be used as an absorbent sink at the downstream end of the test to control sample flow along the strip. Choosing an absorbent with sufficient capacity is an important consideration when designing an assay.

Dipstick Colorimetric Assays

As with other CF grades, CF4 is suitable for use in dipstick colorimetric assays. Dipstick colorimetric assays, in which a cellulose pad is impregnated with a color reagent, are widely used in everything from urine testing to environmental assays. The base cellulose is a key part of the system, and the correct choice of absorbency, wicking rate, and wet strength are critical to producing a working assay. The Cytiva range of cellulose materials for dipstick colorimetric assays offers highly consistent and inert substrates for absorption of the active chemicals required for development of dipstick tests. The purity of the cellulose base material, coupled with Cytiva quality manufacturing practices, make these papers an exceptional choice for large-scale manufacturing. The increased water capacity of CF4 makes it suitable for use in flow-through assays as an absorbent pad.