This product is a collagen Type IV, which contains up to 6 distinct a-chains. The molecular weight may be quite variable and is not determined on a lot-to-lot basis. Historical investigations reveal 3 bands on SDS-PAGE gels with corresponding molecular weights as follows:
Band 1: 102 - 104 kDa
Band 2: 157 - 162 kDa
Band 3: 178 - 181 kDa
In addition, the Merck Index reports a molecular weight of 130 kDa and the CRC reports a molecular weight of 95 kDa or greater.
(Merck Index, 11th ed., p. 387, #2476 / CRC-Collagen, vol. I, Biochemistry, 140 (1988))

