pH Paper and other Test Strips
Single-use test materials used to rapidly and semi-qualitatively determine the acidity or alkalinity of liquids or to measure another parameter or substance; may include tests for starch, chlorine, and molybdenum; usually via the use of color-based reactions.
pH Papers, pH strips, pH sticks, and pH test kits are used in laboratory, industrial, and educational environments to qualitatively assess pH levels or monitor acid-base titrations in a range of sample types.pH Buffer reference standards are used for the accurate calibration of pH meters and monitors for far more precise and quantitative pH measurement.
pH Test papers are supplied either as rolls, tear-off strips, or sticks. They are impregnated with indicator dyes that change color at a specific pH. In some products, indicator dyes are covalently linked to cellulose fibers to avoid bleed-out (leaching) and contamination of the test sample.
Some pH papers indicate simple acid or base conditions with a single red-to-blue color change (also called litmus papers). Universal pH papers and strips contain a combination of indicators that cover a range of pH values up to and including 0 to 14 in a single test. The observed color change is checked against a comparison chart supplied with the papers.
Alternatively, for metered assessments of pH, standard or reference pH buffers are used to calibrate pH meters and other electrochemical sensors.
Standard Buffer Characteristics:
• Typically supplied at fixed values of pH 4.01, pH 7.00, and pH 10.01
• May be color-coded for easy and quick identification
• Certified to their nominal pH and accuracy at a specified temperature (typically 20°C)
• Supplied as ready-to-use solutions or concentrates
• Contain antifungals for extended shelf life
Sigma Aldrich Fine Chemicals Biosciences ExpandTM Long Range dNTPac
The Expand Long Range dNTPack is the second-generation version of the Expand Long Template PCR System optimized and designed to consistently amplify PCR products from 5kb up to 25kb from genomic DNA (or up to 40kb from lambda DNA templates). The supplied buffer can be used for all PCR product sizes. In addition a buffer without MgCl2 and separate vials of MgCl2 and DMSO are included if optimization is needed. Expand Long Range dNTPack contains a special enzyme mix that consists of thermostable Taq DNA Polymerase and a thermostable DNA polymerase with proofreading activity. This powerful polymerase mixture produces a high yield of PCR product. Due to the inherent 3-5 exonuclease activity of the proofreading polymerase Expand Long Range dNTPack copies DNA three times more accurately than Taq DNA Polymerase.
ASI STANDARDS Chlorine in Water Check Standard 50 mg/kg - 100 mL
Chlorine in Water manufactured and certified gravimetrically under the guidance of an ISO 9001 quality management system. When applicable, standards are traceable to NIST certified reference materials.
