MDS INC.

election_required = True...to or less than the Purchase Price or pursuant to a Purchase Price Tender, we will purchase all of your Shares without proration (but otherwise subject to the terms and conditions of the Offer). If you own an “odd lot” of Shares, you must check (or tick) the “Odd Lots” box in either the Letter of Transmittal or the Notice of Guaranteed Delivery. See Section 2 of the Offer to Purchase, “Number of Shares; Proration”. WHEN WILL MDS PAY FOR THE SHARES I DEPOSIT? We will publicly announce the Purchase Price promptly after we have determined it and will take up and pay for Shares to be purchased pursuant to the Offer promptly after 5:00 p.m. (East...

expiry = 2010-03-29...herein. Shareholders who validly deposit Shares without specifying whether they are making an Auction Tender or a Purchase Price Tender will be deemed to have made a Purchase Price Tender. The Offer expires at 5:00 p.m. (Eastern time) on March 29, 2010, unless extended, varied or withdrawn (the “Expiration Date”). MDS expressly reserves the right to withdraw the Offer and not take up and pay for any Shares deposited under the Offer unless certain conditions are satisfied. The Offer is no...

listed = True...ceeds the minimum “liquid market” requirements specified in MI 61-101; (b) the number of Shares to be acquired under the Offer in relation to the public float, the trading volumes of and the number of trades in the Shares on the TSX and the NYSE, the value of trades on the TSX and the NYSE and the market value of the Shares during the twelve month period preceding the announcement of the Offer; (c) the effect that the purchase of the maximum number of Shares that MDS is offering to purchase pursuant to the Offer would have on the aggregate shareholdings of related parties of MDS; and (d) advice from RBC, financial advisor...

mechanism = DUTCH...lders who do not deposit their Shares to the Offer. See Section 2 of the Circular, “Purpose and Effect of the Offer”. WHAT WILL THE PURCHASE PRICE FOR THE SHARES BE AND WHAT WILL BE THE FORM OF PAYMENT? We are conducting the Offer through a procedure called a modified “Dutch Auction”. This procedure allows you to select a price of not more than US$9.30 per Share and not less than US$8.10 per Share at which you are willing to deposit your Shares. As promptly as practicable after 5:00 p.m. (Eastern time) on March 29, 2010, we will, upon the terms and subject to the conditions of the Offer, determine a single Purchase...

mechanism = DUTCH...or the price at which you may choose to tender Shares to the Offer. General 1. What is the MDS Substantial Issuer Bid? A Substantial Issuer Bid (“SIB”) is a process that allows MDS to buy back its shares from shareholders. The MDS SIB is being conducted on a modified “Dutch Auction”. In a modified “Dutch Auction”, a company offers to repurchase a specific number of shares within a set price range up to a pre-determined dollar amount, and shareholders are invited to tender shares during the offer period. Shareholders specify the lowest price within the range that they are willing to accept or can also indicate they...

mechanism = DUTCH...or the price at which you may choose to tender Shares to the Offer. General 1. What is the MDS Substantial Issuer Bid? A Substantial Issuer Bid (“SIB”) is a process that allows MDS to buy back its shares from shareholders. The MDS SIB is being conducted on a modified “Dutch Auction”. In a modified “Dutch Auction”, a company offers to repurchase a specific number of shares within a set price range up to a pre-determined dollar amount, and shareholders are invited to tender shares during the offer period. Shareholders specify the lowest price within the range that they are willing to accept or can also indicate they...

priority = True...Price Tenders, will receive the Purchase Price, payable in cash (but subject to applicable withholding taxes, if any), for all Shares purchased, upon the terms and subject to the conditions of the Offer, including the provisions relating to proration and the preferential acceptance of odd lots described below. MDS will first accept for purchase Shares validly deposited by any Shareholder who beneficially holds, as of the close of business on the Expiration Date, odd lots of fewer than 100 Shares in the aggregate and who deposits all such Shares pursuant to an Auction Tender at a price equal to or less than the Purchase Price o...

threshold = 100...luding the provisions relating to proration and the preferential acceptance of odd lots described below. MDS will first accept for purchase Shares validly deposited by any Shareholder who beneficially holds, as of the close of business on the Expiration Date, odd lots of fewer than 100 Shares in the aggregate and who deposits all such Shares pursuant to an Auction Tender at a price equal to or less than the Purchase Price or pursuant to a Purchase Price Tender. Shareholders validly depositing Shares pursuant to Auction Tenders at US$8.10 per Share (the minimum purchase price under the Offer) and Shareholders validly depositin...

txn_type = TENDER_OFFER...specified by the depositing Shareholders of not more than US$9.30 and not less than US$8.10 per Share (“Auction Tenders”), or (ii) purchase price tenders (“Purchase Price Tenders”), in either case upon the terms and subject to the conditions set forth in this offer to purchase (the “Offer to Purchase”) and in the accompanying letter of transmittal (the “Letter of Transmittal”). Shareholders who wish to deposit Shares without specifying a price at which such Shares may be purchased by the Corporation should make a Purchase Price Tender. Under a Purchase Price Tender, Shares will be purchased, upon the terms and...

txn_type = TENDER_OFFEREX-99.A.5.B 2 o59830aexv99waw5wb.htm EX-99.A.5.B exv99waw5wb Exhibit (a)(5)(B) Substantial Issuer Bid Employee Q&A Any information in this Employee Q&A is subject to the information contained in the Offer to Purchase, the Circular and the Letter of Transmittal. Therefore, we urge you to carefully read the Offer to Purchase, the Circular and the Letter of Transmittal in their entirety prior to making any decision regarding whether or not to tender your Shares or the price at which you may choose to tender Shares to the Offer. General 1. What is the MD...

txn_type = TENDER_OFFEREX-99.(A)(5)(B) 2 o60268exv99wxayx5yxby.htm EX-99.(A)(5)(B) exv99wxayx5yxby Substantial Issuer Bid Employee Q&A Any information in this Employee Q&A is subject to the information contained in the Offer to Purchase, the Circular and the Letter of Transmittal. Therefore, we urge you to carefully read the Offer to Purchase, the Circular and the Letter of Transmittal in their entirety prior to making any decision regarding whether or not to tender your Shares or the price at which you may choose to tender Shares to the Offer. General 1. What is the MD...

txn_type = ISSUER_BID...inc.com For Immediate Release: MDS Announces Preliminary Results of Share Buyback OTTAWA, Canada, March 30, 2010 — MDS Inc. (TSX: MDS; NYSE: MDZ), a leading provider of products and services to the global health science markets, today announced results of its substantial issuer bid (the “Bid”), which expired at 5 p.m. (Eastern time) on March 29, 2010. Based on preliminary results, MDS Inc. (“MDS”) will accept for purchase and cancellation 52,941,176 common shares in the capital of MDS (the “Common Shares”) at a purchase price of US$8.50 per Common Share, totalling US$450 million in accordance with the terms of the...