Reductive methylation has been used to radioactively label crude-extract proteins with 3H or 14C. The procedure achieved good isotope incorporation and resolution of proteins on two-dimensional polyacrylamide gels. It allows high-precision comparison of tissue samples by double-labelling and should facilitate the study of tissue proteins by two-dimensional gel electrophoresis.

The amount of 140 individual proteins of E. coli B/r was measured during balanced growth in five different media. The abundance of each protein was determined from its absolute amount in 14C-glucose-minimal medium and a measurement of its relative amount at each growth rate using a double labeling technique. Separation of the proteins was carried out by two-dimensional gel electrophoresis. This...

A new method for spot matching in two-dimensional gel electrophoresis images using a cumulative frequency matrix is proposed. The method improves on the weak points of the previous method called 'spot matching by topological patterns of neighbour spots'. It accumulates the frequencies of neighbour spot pairs produced through the entire matching process and determines spot pairs one by one in or...

In this paper, the authors present a hybrid genetic approach for the two-dimensional rectangular guillotine oriented cutting-stock problem. In this method, the genetic algorithm is used to select a set of cutting patterns while the linear programming model permits one to create the lengths to produce with each cutting pattern to fulfil the customer orders with minimal production cost. The effec...

Consider two graphs, G1 and G2, on the same vertex set V , with |V | = n and Gi having mi edges for i = 1, 2. We give a simple algorithm that partitions V into sets A and B such that eG1(A,B) ≥ m1/2 and eG2(A,B) ≥ m2/2−∆(G2)/2. We also show, using a probabilistic method, that if G1 and G2 belong to certain classes of graphs, (for instance, if G1 and G2 both have a density of at least 2/3, or if...

A method for separation and purification of plant hormones auxin and abscisic acid based on mixed mode reversed-phase anion-exchange solid phase extraction and two-dimensional HPLC was developed. Two-dimensional HPLC in "heart cutting" mode was very efficient in the purification of these two hormones. Its purification power is high enough to allow reliable on-line quantification of both hormone...