Name: Factor P Depleted Serum
SKU: A339C
Price: 100.00 USD
Availability: InStock

Description

General Description

Normal human serum was depleted of factor P (properdin) by immunoaffinity chromatography. The product is tested for the absence of factor P by double immunodiffusion. Factor P is a positive regulator of alternative pathway complement activation. As a result, Factor P-Dpl is still capable of activating the alternative pathway but activation is slower than with properdin present. For example, lysis of rabbit erythrocytes by Factor P-Dpl requires 20-25 min to reach 50% without properdin, but with P added back or in NHS lysis requires only 5-7 min under otherwise identical conditions. Factor P-Dpl is certified to possess a functional alternative pathway for complement activation which is fully functional if reconstituted with properdin. Full reconstitution requires addition of 10 µg factor P/mL serum (Law, S.K.A. and Reid, K.B.M. (1995)). The normal human serum concentration of factor P has been variously reported to be between 4 and 20 µg/mL (Morley, B.J. and Walport, M.J. (2000); Morgan, B.P. (2000); Dodds, A.W. and Sim, R.B. (1997)).

Specifications

Sizes Available: 1.0 mL/vial
Concentration: >50 mg protein/mL (see Certificate of Analysis for actual conc.)
Form: Frozen liquid
Activity: >80% versus NHS standard after reconstitution with factor P
Purity: No factor P detectable by immunodiffusion
Buffer: 10 mM sodium phosphate, 145 mM NaCl, pH 7.3
Preservative: None, 0.22 µm filtered
Storage: -70o C or below. Minimize freeze/thaw cycles.
Source: Normal human serum (shown by certified tests to be negative for HBsAg and for antibodies to HCV, HIV-1 and HIV-II).
Precautions: Use normal precautions for handling human blood products.
Origin: Manufactured in the USA.

Safety and Handling

Precautions/Toxicity/Hazards

The source is human serum, therefore precautions appropriate for handling any blood-derived product must be used even though the source was shown by certified tests to be negative for HBsAg and for antibodies to HCV, HIV-1 and HIV-II.
Hazard Cod: B WGK Germany 3
MSDS is available upon request.

Additional Information

Physical Characteristics & Structure

Factor P-Dpl is supplied as a clear, straw-colored liquid containing all proteins of normal human serum except complement factor P (properdin) and C1q.

Function

Factor P-Dpl serum is not completely functionally deficient in alternative pathway activity, but without factor P the feedback loop of the alternative pathway does not activate or amplify as rapidly as with properdin present. The depleted serum is reconstituted with 10 µg/mL factor P (CompTech #A139) and tested to verify that a fully functional alternative pathway is restored. It is tested for alternative pathway function using rabbit erythrocytes (CompTech #B300). The Certificate of Analysis provided with each lot gives a description of the assays and specific titers for the depleted and reconstituted sera compared to normal human serum. Because the only difference in alternative pathway activity between Factor P-Dpl, reconstituted P-Dpl and NHS is the time to activation, a graph of the time course of each of these assays is provided with the Certificate of Analysis.