ALPHASIN� ELASTASE DIFFUSION PLATE, No. A622
DISCUSSION.The enzymatic activity of pancreatic elastase on its natural substrate has been shown to be inhibited by the serum protein alpha-1-antitrypsin (AAT) (12, 13). The inhibition of elastase by serum, the elastase inhibitory capacity (EIC), is proportional to the serum level of AAT (14, 15). Studies (14, 15) indicate that reduced EIC is characteristic of serum from individuals having AAT deficiency. EIC may be readily estimated from radial diffusion of elastase-serum mixtures in elastin impregnated agar gel (16).Development of the Alphasin� elastase diffusion plate by Elastin Products Company, Inc. is an outgrowth of this research. The report by Senior et al. (16) documents the technique as a reliable method for screening serum for EIC. In our testing, an estimate of EIC is rapidly and inexpensively determined.
The Alphasin� plate is a square, plastic Petri dish containing 10 ml of buffered (pH 8.8 at 37° C) agar gel that is uniformly impregnated with Elastin-Fluorescein of particle size smaller than 37 micron (product No. ES80). The gel contains 25 wells 4 mm in diameter and is protected from desiccation by polyethylene film and an absorbent mat saturated with water. Each plate is sealed in a polyethylene bag that is used as a moisture chamber during incubation.The Alphasin� technique combines economy and simplicity. The assay does not require specialized equipment and requires only a minimal allotment of time. These advantages allow rapid screening of large numbers of sera for EIC. A procedure for screening EIC is given in Methods. The Alphasin� plate may also be used to estimate the elastolytic activity of biological media according to published method (16, 17, 18).
Measuring Template No, M622 is used for measuring the diameters of zones of solubilization in the elastase diffusion plate. Scaled for reading 2-14 mm in diameter; graduated in 0.1 mm subdivisions. Re-usable many times, made of plastic film.
The elastase diffusion plate can be prepared in the laboratory using Elastin-Fluorescein or Elastin-Rhodamine as substrate (particle size smaller than 37 micron). The preparation is given in Methods.
The plates should be stored within an air-tight container such as a polyethylene bag. Store at 5° C. DO NOT FREEZE. The shelf life is approximately 4 months at 5°C. An expiration date is indicated on the label.
Alphasin� plates are available PRE-CUT containing 25 wells 4 mm in diameter and as BLANKS ready for ptttern perforation. Since each quadrant is designated by a letter and a number, several patterns can be cut using the quadrants as guides. In addition sampled wells can be efficiently tabulated according to letter and number.
- No. A622, Pre-cut containing 25 4 mm Wells
- No. A622B, Blank, without wells
The plates are prepared upon receipt of purchase order. All plates are shipped only Federal Express Next Day Service. FOB Owensville, Missouri.