Analytical isoelectric locusmg (i) is one ol the high resolving power methods for protein analysis

and is also important to characterize |3-lactamases by determining .their isoslectric points in a stable

continuous and linear pH gradient. In this study

we improved the traditional method by setting up an ultra thin--layer polyacrylamide gel IEF to characterize p-lactamases of Gram-negative bacteria. This improved method has many advantages. Many samples ran be analyzed within one block of gel. It is easy to perform and the time for electro-phoresis is greatly shortened. Only small volume of sample is needed and the resolving power is high. The amount of reagents used is much reduced and cost lowered. By changing certain conditions

it can also be used to seperate and analyze other biological material. Thus

we believe this improved method is valuable and is highly recommendable in biochemical researches