l.L'NDSTKOM IDENTIFICATION OF FISH SPE( IKS 



FlOl'RE 3. — Sarcoplasmic protein patterns 

 from seven species of fishes focused in a pH 

 3.5-5 gradient under constant power condi- 

 tions. The species are from left to right: 

 winter flounder, Pseudopleuronectes ameri- 

 canus; American plaice, Hippoglossoides 

 platessoides; gray sole, Glyptocephalus 

 cynoglossus; yellowtail, Lunanda ferru- 

 ginea; ocean perch, Sebastes marinus; cusk, 

 Brosme brosme; and whiting, Merluccius 

 bilinearis. 



FIGURE 4. — Sacroplasmic protein patterns 

 from seven species of fishes focused in a pH 

 3.5-5 gradient under constant voltage con- 

 ditions. The species arrangement is the 

 same as shown in Figure 3. Figures 3 and 4 

 illustrate the reproducibility of the protein 

 patterns for seven species of fishes on two 

 successive days. 



cj as 



w m 

 a q 







3 M 



c < 

 m 



uj or 

 O a- 



D 



u 



zone at a particular position to obtain a satisfac- 

 tory separation. Isoelectric focusing is actually 

 less demanding in experimental technique when 

 compared to electrophoresis, yet still offers in- 

 creased resolution and reproducibility. 



Due to the limited number of individuals and 

 species studied, additional work is underway to 

 increase the reliability and potential of IEF as a 

 species identification test. Additional species will 

 be compared. Their protein patterns will be added 

 to a library of standard IEF protein patterns. 



Additional individuals from each species will be 

 tested for variations in protein patterns due to 

 size, sex, season, or geographical origin. Varia- 

 tions in some minor components of the protein 

 patterns for some species after frozen storage have 

 been observed. Work is planned to examine this 

 in greater detail. The use of commercially pre- 

 pared polyacrylamide gel slabs will reduce varia- 

 tions in stabilizing media composition and elim- 

 inate gel preparation time. These ready prepared 

 gels used with a high-voltage constant-power 



575 



