TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The crystalline form further comprises peaks at 2 theta values of 15.6 plus minus 0.3, 19.9 plus minus 0.3, 22.4 plus minus 0.3, 23.2 plus minus 0.3, 24.8 plus minus 0.3, 29.0 plus minus 0.3, 38.6 plus minus 0.3 and 48.8 plus minus 0.3. The intensity of any of the peaks is more than 10% of the intensity of the most intense of the peaks.    TECHNOLOGY FOCUS - PHARMACEUTICALS - Preferred Method: The penicillin G acylase is immobilized. The method is carried out at 0-5 degrees C and at a pH of 8.4-9.1. The pH is maintained by means of adding an aqueous solution of lithium hydroxide, potassium hydroxide and/or sodium hydroxide. The product (I) is isolated by means of crystallization and filtration or centrifugation. The isolation is preceded by removal of 50-90% of liquid by means of filtration and addition of an organic solvent. In the method, when R1 is a radical (iia) with R3 is CH3 or radical (iib), the mixing is with D-4-hydroxyphenylglycine ethyl ester or with D-4-hydroxyphenylglycine methyl ester. When R1 is a radical (iia) with R3 is CH3, the method further involves: reacting the compound (I) with a derivative of 4-ethyl-2,3-dioxo-1-piperazinecarboxylic acid or a derivative of 4-hydroxy-6-methyl-nicotinic acid to give cefoperazone or cefpiramide respectively. Preferred Components: The penicillin G acylase is penicillin G acylase AA or penicillin G acylase mutant 1. ACTIVITY - Antibacterial. No biological data given.    MECHANISM OF ACTION - None given.    EXAMPLE - Enzymatic preparation of cefatrizine was carried out follows: 7-amino-3-(1,2,3-triazol-4-ylthiomethyl)-3-cephem-4-carboxylic acid (7-TACA, 1.03 g) was added to distilled water (50 g) and cooled to 3 degrees C. The mixture was stirred at 400 rpm and the pH was brought to 8.0 with aqueous NaOH (5M). Immobilized penicillin G acylase mutant 1 (5 g,) was added and to the resulting mixture a solution of D-4-hydroxyphenylglycine methylester (HPGM) was dropped at speed of 7 ml/hour by a syringe pump. This solution was prepared by dissolving HPGM (0.68 g) in water (5 g) and 25% H2SO4 (0.5 g in water). The enzymatic reaction was followed by analytical HPLC for 24 hours. At the end of HPGM addition, the mixture contained 0.46 (wt./wt.%) D-4-hydroxyphenylglycine (HPG), 0.02 (wt./wt.%) HPGM, 1.29 (wt./wt.%) 7-TACA and 0.77 (wt./wt.%) of cefatrizine (the amount of cefatrizine was calculated using a response factor estimated from the mass balance). After stirring the reaction overnight, the product was hydrolyzed and the mixture contained 0.91 (wt./wt.%) D-4-hydroxyphenylglycine (HPG), 0.01 (wt./wt.%) HPGM and 1.93 (wt./wt.%) 7-TACA.