Blood coagulation factor VIII: An overview.

Factor VIII (FVIII) functions as a co-factor in the blood coagulation cascade for the proteolytic activation of factor X by factor IXa. Deficiency of FVIII causes hemophilia A, the most commonly inherited bleeding disorder. This review highlights current knowledge on selected aspects of FVIII in which both the scientist and the clinician should be interested.

ELISA using enzyme penicillinase for the detection of IgG antibodies to Trypanosoma evansi in sera of experimentally infected rabbits.

An Enzyme Linked Immunosorbent Assay (ELISA) using penicillinase as an enzyme marker has been developed for the detection of IgG antibodies in the sera of Trypanosoma evansi infected rabbits. Anti-T. evansi IgG antibodies were detected on 10th day after the infection and thereafter antibody titre rose progressively for 18 days. The developed assay is simple (end result assessed visually) and reproducible (4.4 and 14.0 percentage of intra and inter coefficient of variation respectively).

Strip ELISA for the detection of IgG antibodies to Toxoplasma gondii.

An enzyme linked immunosorbent assay (ELISA) has been developed using a polycarbonate coated strip and penicillinase for the detection of IgG antibodies to T. gondii. Of 40 serum samples from patients clinically suspected to have toxoplasma infection, 24 were positive for IgG antibodies to T. gondii. Strip ELISA showed 95.83 per cent sensitivity and 89.4 per cent specificity. This method is simple (end result assessed visually), sensitive (detection of antitoxoplasma IgG antibodies to a level of 15 IU/ml) and reproducible (5.9 and 11.6 intra and inter percentage of coefficient of variation respectively).

Penicillinase as a potential enzyme marker for enzyme linked immunosorbent assay and its application in immunodiagnostics.

The present review article deals with the application of penicillinase in enzyme linked immunosorbent assay (ELISA) and describes the various characteristics of penicillinase. Using penicillinase as an enzyme marker, few kits have been developed to detect physiologically active proteins, infectious diseases and toxins. The review also highlights briefly the source of penicillinase, its production, isolation, purification and certain molecular properties.

Usage of penicillinase as an enzyme marker in enzyme linked immunosorbent assay for the detection of IgG antibodies to Toxoplasma gondii.

An Enzyme linked immunosorbent assay system has been developed using penicillinase as an enzyme marker for the detection of IgG antibodies to Toxoplasma gondii. This system is simple (end result assessed visually) reliable (the results are matching with other available commercial ELISA based kit), sensitive (detection of antitoxoplasma IgG antibodies to a level of 15 IU/ml) and reproducible (4.3 & 6.7% intra and inter coefficient of variation respectively). Experimental results with human serum samples using our system has shown consistent results and were in total agreement with other commercially available diagnostic kits. It is therefore suggested that ELISA system using penicillinase can be a simple, sensitive and reliable method for the diagnosis of toxoplasmosis in human.

Detection of toxoplasma IgM antibodies by ELISA method: a comparative study of different enzymes as markers.

Detection of toxoplasma IgM antibodies by employing enzyme linked immunosorbent assay (ELISA) technique was developed using different enzymes viz, horseradish peroxidase (HRP) (EC. 1.11.17), urease (EC. 3.5.15) and penicillinase (EC 3.5.2.6) as markers. Of these enzymes, HRP is light sensitive and needs dark chamber, also inactivated by preservative sodium azide. Similarly urease test system is extremely pH sensitive and demands special care during ELISA technique. Whereas penicillinase showed certain distinct advantages viz. stable at room temperature, high specific activity and economical. In the present studies it was observed that the sensitivity of penicillinase is similar to HRP and urease, marker enzymes used in commercially available diagnostic kit. The prominent feature of detection of toxoplasma IgM antibodies involving these three enzymes are: a) Shorter incubation time (About 2.5 hours) b) No false positive reaction. Moreover, these enzyme conjugates were prepared from F (ab')2 fragments of antitoxoplasma rabbit serum to elicit specific interaction with IgM antibodies only, avoiding cross interaction with other non-specific proteins like compliment systems and rheumatoid factor.