The phrase "as a second purification" is correct and usable in written English.
It can be used in contexts discussing processes or methods that involve multiple stages of purification or cleansing.
Example: "The water treatment facility employs a two-step process, with the first stage being filtration and as a second purification, chemical treatment is applied."
Alternatives: "as an additional purification" or "as a subsequent purification".
Activated alumina was used as a second purification step.
As a second purification step for p53 orthologs, heparin affinity chromatography was used.
As a second purification step, this 32 kDa material was resolved by reducing PAGE, after which the material migrating at approximately 18 kDa was recovered.
In our attempts to enrich the fraction of rEPOELD carrying sialylated glycoforms, we performed SNA lectin chromatography as a second purification step.
After a second purification as above, both Cy5- and Cy3-labeled cDNAs were pooled.
As a first purification step, RBC membrane extracts (prepared from random, Vel+ blood donors) were resolved by non-reducing polyacrylamide-gel electrophoresis (PAGE), and the material migrating at approximately 32 kDa was recovered by electro-elution.
A second purification step by ion-pair chromatography on Lichroprep RP-18 was effective in removing these contaminants, giving pure 5 as the triethylammonium salt.
Our initial intention was to trial a number of different ATP-coupled resins for use as a second affinity-purification step.
Fig. 3 Cation-exchange chromatography as second purification step using an SP Sepharose FF column; ABTS oxidizing enzyme activity was detected in the area with a gray background; UV absorption in AU at 28 nm (blue line), detected activity (dashed line), buffer concentration (50 mM sodium acetate buffer pH 4.0 with 1 M NaCl) in % (light gray line).
Based on the protein yield and the number of maleimides, the column and dialysis purification methods were chosen as the first and second purification procedure, respectively.
Furthermore, acylation with reagents that reversed the charge of the primary amines did not affect rmCRPs hydrophobic binding characteristics, allowing for large scale, efficient use of hydrophobic adsorption chromatography as a first step in purification.
