Serum albumin, bovine 10 percent

The extent of cell growth as indicated by total protein concentration was done using the Folin-Phenol method of Lowry (4) with a bovine serum albumin standard on cell samples solubilized with 0.05% sodium lauryl sulfate. Data are presented as percent inhibition of cell growth relative to untreated controls. 

Figure 1 Relationships of S with interfacial tension and emulsifying activity of proteins. I, bovine serum albumin 2, /3-lactoglobulin 3. trypsin 4, ovalbumin 5, conalbuntin 6, lysozyme 7, K-casein 8, 9, I0, II, and 12, denatured ovalbumin by heating at 85°C for l, 2, 3, 4, and 5 min respectively 13, 14, 15, 16. 17, and 18. denatured lysozyme by heating at 85"C for l, 2, 3, 4, 5, and 6 min respectively 19, 20, 21, 22, and 23, ovalbumin bound with 0.2, 0.3, 1.7, 5.7, and 7.9 mol of sodium dodecyl sulfate/mol of protein respectively 24, 25, 26, 27, and 28, ovalbumin bound with 0.3, 0.9, 3.1,4.8, and 8.2 mol of linoleate/mol of protein respectively. Interfacial tension measured at corn oil/0.20c protein interface with a Fisher Surface Tensiontat Model 21. Emulsifying activity index calculated from the absorbance at 500 nm of the supernatant after centrifuging blended mixtures of 2 ml of corn oil and 6 ml of 0.5% protein in 0.01 M phosphate buffer, pH 7.4 S initial slope of fluorescence intensity (FI) vs. percent protein plot. 10 /al of 3.6 mM m-parinaric acid solution was added to 2 ml of 0.002 to 0.1% protein in 0.01 M phosphate buffer, pH 7.4, containing 0.002% SDS. FI was measured at 420 nm by exciting at 325 nm. (From Ref. 2. Reprinted by permission.)...

Oliveira and Cass described a method for the analysis of cephalosporin antibiotics in bovine milk using RAM columns for on-line sample clean-up. The system was composed of a RAM bovine serum albumin (BSA) phenyl column coupled to a C18 analytical column. Milk samples were directly injected after addition of 0.8 mM solution of tetrabutylammonium phosphate. The standard curve was linear over the range 0.100-2.50 tig/ml for five cephalosporin antibiotics (cefoperazone, cephacetril, cephalexin, cephapirin, and ceftiofur). The limits of quantification and detection reported were 0.100 and 0.050 ttg/ml, respectively. The method showed high intermediate precision [coefficient of variation percent (CV%) 2.37-2.63] and recovery (CV% 90.7-94.3) with adequate sensitivity for drug monitoring in bovine milk samples. 

Deterniine the percent incorporation by TCA precipitation. Remove 2 oL of the reaction mix. Add 8 jL of DEPC-treated H O, and spot 5 pL onto a Whatman GFC filter and reserve it. To the other 5 pL, add 25 pL of 2 mg/mL bovine serum albumin (BSA) and 100 pL of 20% trichloroacetic acid (TCA). Incubate on ice for 30 min, and then filter through GFC in a vacuum filtration device. Wash with 20 mL of 5% TCA, and then dry the filter for 20 min at 60°C or under a heat lamp. Transfer both filters to scintillation vials, add scintillation fluid, and count. Determine the percent incorporation of the trace label into cDNA. The yield in nanograms of cDNA is incorporation xl20 (nmol each nucleotide) x4 (nucleotides) x330 (g/mol of nucleotide). 

The blot made by either of the methods named above can be used for further studies. Suppose that there is a particular protein whose presence you were interested in determining. All you have to do now is to probe the blot with an antibody specific for this protein. To do this the first step is treat the entire paper with a 10 percent bovine serum albumin preparation. This is necessary because of the tendency of proteins to bind nitrocellulose through hydrophobic interactions. So that the antibody, which too is a protein, does not bind through non-specific association, it is necessary that all open sites on nitrocellulose are blocked first. Once this incubation is over the specific antibody is incubated with the blot. The antibody will bind if the corresponding antigen is present on the paper. Otherwise it will be washed off. 

More precisely, cell suspensions were aliquoted in Eppendorf tubes containing Krebs Ringer. Bicarbonate Buffer (KRBB) supplemented with 4% (w / v) bovine serum albumin (BSA), ImM glucose and 0,278 pCi of " C-phenanthrene (0.0066 pmol/1) or 0.296 pCi of " C-pyrene (0.007 pmol/1) or 0,272 pCi of " C-benzo[a]pyrene (0,0065 pmol/1). After different incubation time at 37°C under gentle agitation (40 r.p.m) with or without insulin (90 nM), aliquots of the media were removed for radioactivity determination by liquid scintillation (Ultima Gold) counting in a Packard Tricarb in order to determine the percent of extra cellular radioactivity. 

---